"Flows" trigger can't have null conditions
### Expected Behavior

_No response_

### Actual Behaviour

Following the rework on multiple conditions, having a Flow trigger with no conditions leads to a crash of the instance

### Steps To Reproduce

_No response_

### Environment Information

- Kestra Version: 0.12.0-SNAPSHOT
- Operating System (OS / Docker / Kubernetes):
- Java Version (If not docker):


### Example flow

_No response_
core/src/main/java/io/kestra/core/services/AbstractFlowTriggerService.java
core/src/main/java/io/kestra/core/services/AbstractFlowTriggerService.java
core/src/test/java/io/kestra/core/runners/MultipleConditionTriggerCaseTest.java core/src/test/java/io/kestra/core/runners/RestartCaseTest.java core/src/test/java/io/kestra/core/tasks/flows/BadFlowableTest.java core/src/test/java/io/kestra/core/tasks/flows/PauseTest.java core/src/test/resources/flows/valids/trigger-flow-listener-no-condition.yaml
diff --git a/core/src/main/java/io/kestra/core/services/AbstractFlowTriggerService.java b/core/src/main/java/io/kestra/core/services/AbstractFlowTriggerService.java
index 80ae142b6d..acbc6e1076 100644
--- a/core/src/main/java/io/kestra/core/services/AbstractFlowTriggerService.java
+++ b/core/src/main/java/io/kestra/core/services/AbstractFlowTriggerService.java
@@ -53,7 +53,7 @@ public List<Execution> computeExecutionsFromFlowTriggers(Execution execution, Li
             .flatMap(flow -> flowTriggers(flow).map(trigger -> new FlowWithFlowTrigger(flow, trigger)))
             .filter(flowWithFlowTrigger -> conditionService.valid(
                 flowWithFlowTrigger.getFlow(),
-                flowWithFlowTrigger.getTrigger().getConditions().stream()
+                Optional.ofNullable(flowWithFlowTrigger.getTrigger().getConditions()).stream().flatMap(Collection::stream)
                     .filter(Predicate.not(MultipleCondition.class::isInstance))
                     .toList(),
                 conditionService.conditionContext(
@@ -67,7 +67,7 @@ public List<Execution> computeExecutionsFromFlowTriggers(Execution execution, Li
         if (multipleConditionStorage.isPresent()) {
             List<FlowWithFlowTriggerAndMultipleCondition> flowWithMultipleConditionsToEvaluate = validTriggersBeforeMultipleConditionEval.stream()
                 .flatMap(flowWithFlowTrigger ->
-                    flowWithFlowTrigger.getTrigger().getConditions().stream()
+                    Optional.ofNullable(flowWithFlowTrigger.getTrigger().getConditions()).stream().flatMap(Collection::stream)
                         .filter(MultipleCondition.class::isInstance)
                         .map(MultipleCondition.class::cast)
                         .map(multipleCondition -> new FlowWithFlowTriggerAndMultipleCondition(

diff --git a/core/src/test/java/io/kestra/core/runners/MultipleConditionTriggerCaseTest.java b/core/src/test/java/io/kestra/core/runners/MultipleConditionTriggerCaseTest.java
index 0e37819d6e..4a5b70ceda 100644
--- a/core/src/test/java/io/kestra/core/runners/MultipleConditionTriggerCaseTest.java
+++ b/core/src/test/java/io/kestra/core/runners/MultipleConditionTriggerCaseTest.java
@@ -44,7 +44,7 @@ public void trigger() throws InterruptedException, TimeoutException {
         executionQueue.receive(either -> {
             Execution execution = either.getLeft();
             synchronized (ended) {
-                if (execution.getState().getCurrent() == State.Type.SUCCESS) {
+                if (execution.getState().getCurrent() == State.Type.SUCCESS && !execution.getFlowId().equals("trigger-flow-listener-no-condition")) {
                     if (!ended.containsKey(execution.getId())) {
                         ended.put(execution.getId(), execution);
                         countDownLatch.countDown();
@@ -93,7 +93,7 @@ public void failed() throws InterruptedException, TimeoutException {
         executionQueue.receive(either -> {
             synchronized (ended) {
                 Execution execution = either.getLeft();
-                if (execution.getState().getCurrent().isTerminated()) {
+                if (execution.getState().getCurrent().isTerminated() && !execution.getFlowId().equals("trigger-flow-listener-no-condition")) {
                     if (!ended.containsKey(execution.getId())) {
                         ended.put(execution.getId(), execution);
                         countDownLatch.countDown();
diff --git a/core/src/test/java/io/kestra/core/runners/RestartCaseTest.java b/core/src/test/java/io/kestra/core/runners/RestartCaseTest.java
index bc28e3b931..93e97bf8ea 100644
--- a/core/src/test/java/io/kestra/core/runners/RestartCaseTest.java
+++ b/core/src/test/java/io/kestra/core/runners/RestartCaseTest.java
@@ -48,7 +48,7 @@ public void restartFailedThenSuccess() throws Exception {
 
         // wait
         Execution finishedRestartedExecution = runnerUtils.awaitExecution(
-            execution -> execution.getState().getCurrent() == State.Type.SUCCESS,
+            execution -> !execution.getFlowId().equals("trigger-flow-listener-no-condition") && execution.getState().getCurrent() == State.Type.SUCCESS,
             throwRunnable(() -> {
                 Execution restartedExec = executionService.restart(firstExecution, null);
                 executionQueue.emit(restartedExec);
diff --git a/core/src/test/java/io/kestra/core/tasks/flows/BadFlowableTest.java b/core/src/test/java/io/kestra/core/tasks/flows/BadFlowableTest.java
index 1502fbae79..3438ad8d43 100644
--- a/core/src/test/java/io/kestra/core/tasks/flows/BadFlowableTest.java
+++ b/core/src/test/java/io/kestra/core/tasks/flows/BadFlowableTest.java
@@ -1,11 +1,14 @@
 package io.kestra.core.tasks.flows;
 
 import io.kestra.core.models.executions.Execution;
+import io.kestra.core.models.executions.TaskRun;
 import io.kestra.core.models.flows.State;
 import io.kestra.core.runners.AbstractMemoryRunnerTest;
 import org.junit.jupiter.api.Test;
 
+import java.util.Arrays;
 import java.util.concurrent.TimeoutException;
+import java.util.stream.Collectors;
 
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.hasSize;
@@ -16,7 +19,7 @@ public class BadFlowableTest extends AbstractMemoryRunnerTest {
     void sequential() throws TimeoutException {
         Execution execution = runnerUtils.runOne("io.kestra.tests", "bad-flowable");
 
-        assertThat(execution.getTaskRunList(), hasSize(2));
+        assertThat("Task runs were: "+ execution.getTaskRunList().stream().map(TaskRun::getTaskId).toList(), execution.getTaskRunList(), hasSize(2));
         assertThat(execution.getState().getCurrent(), is(State.Type.FAILED));
     }
 
diff --git a/core/src/test/java/io/kestra/core/tasks/flows/PauseTest.java b/core/src/test/java/io/kestra/core/tasks/flows/PauseTest.java
index 92e0cc1f09..bfe260d457 100644
--- a/core/src/test/java/io/kestra/core/tasks/flows/PauseTest.java
+++ b/core/src/test/java/io/kestra/core/tasks/flows/PauseTest.java
@@ -66,7 +66,7 @@ public void run(RunnerUtils runnerUtils) throws Exception {
             );
 
             execution = runnerUtils.awaitExecution(
-                e -> e.getState().getCurrent() == State.Type.SUCCESS,
+                e -> !e.getFlowId().equals("trigger-flow-listener-no-condition") && e.getState().getCurrent() == State.Type.SUCCESS,
                 () -> executionQueue.emit(restarted),
                 Duration.ofSeconds(5)
             );
@@ -81,7 +81,7 @@ public void runDelay(RunnerUtils runnerUtils) throws Exception {
             assertThat(execution.getTaskRunList(), hasSize(1));
 
             execution = runnerUtils.awaitExecution(
-                e -> e.getState().getCurrent() == State.Type.SUCCESS,
+                e -> !e.getFlowId().equals("trigger-flow-listener-no-condition") && e.getState().getCurrent() == State.Type.SUCCESS,
                 () -> {},
                 Duration.ofSeconds(5)
             );
@@ -104,7 +104,7 @@ public void runTimeout(RunnerUtils runnerUtils) throws Exception {
                 Duration.ofSeconds(5)
             );
 
-            assertThat(execution.getTaskRunList().get(0).getState().getHistories().stream().filter(history -> history.getState() == State.Type.PAUSED).count(), is(1L));
+            assertThat("Task runs were: " + execution.getTaskRunList().toString(), execution.getTaskRunList().get(0).getState().getHistories().stream().filter(history -> history.getState() == State.Type.PAUSED).count(), is(1L));
             assertThat(execution.getTaskRunList().get(0).getState().getHistories().stream().filter(history -> history.getState() == State.Type.RUNNING).count(), is(1L));
             assertThat(execution.getTaskRunList().get(0).getState().getHistories().stream().filter(history -> history.getState() == State.Type.FAILED).count(), is(1L));
             assertThat(execution.getTaskRunList(), hasSize(1));
diff --git a/core/src/test/resources/flows/valids/trigger-flow-listener-no-condition.yaml b/core/src/test/resources/flows/valids/trigger-flow-listener-no-condition.yaml
new file mode 100644
index 0000000000..158d1df227
--- /dev/null
+++ b/core/src/test/resources/flows/valids/trigger-flow-listener-no-condition.yaml
@@ -0,0 +1,15 @@
+id: trigger-flow-listener-no-condition
+namespace: io.kestra.tests
+
+inputs:
+  - name: from-parent
+    type: STRING
+
+tasks:
+  - id: only-listener
+    type: io.kestra.core.tasks.debugs.Return
+    format: "simple return"
+
+triggers:
+  - id: listen-flow
+    type: io.kestra.core.models.triggers.types.Flow
\ No newline at end of file
