We can have default time range to 1H instead of 30 days 👍  Let's wait for some analysis ;) 

But we use 7 days for some pages, we might decide to align this page also. Locally, it correctly uses the `logs_namespace_flow` index.

As we switch from 30 days to 7 days in other places I advise to do the same here.

For the record the SQL query is:

```sql
select "value" from logs where ("tenant_id" is null and "deleted" = false and (level in ('ERROR'::log_level, 'WARN'::log_level)) and "timestamp" >= cast('2023-09-24 15:30:39.253+02:00' as timestamp with time zone) and "timestamp" <= cast('2023-10-24 15:30:39.253+02:00' as timestamp with time zone)) order by "timestamp" desc fetch next 10 rows only
```
 > As we switch from 30 days to 7 days in other places I advise to do the same here.

I was wrong, apparently we use 30 days by default in all dashboards (homepage, flows, executions, namespaces, ...)
[JDBC] Errors logs widget is long to fetch on the Homepage
### Explain the bug

See https://preview-oss.kestra.io/ui/dashboard

The "Errors logs" widget is long to fetch on the Homepage

### Environment Information

- Kestra Version: 0.13.0-SNAPSHOT
- Operating System and Java Version (if not using Kestra Docker image):

jdbc-h2/src/main/resources/migrations/h2/V1_16__log_timestamp_index.sql jdbc-mysql/src/main/resources/migrations/mysql/V1_16__log_timestamp_index.sql jdbc-postgres/src/main/resources/migrations/postgres/V1_16__log_timestamp_index.sql
diff --git a/jdbc-h2/src/main/resources/migrations/h2/V1_16__log_timestamp_index.sql b/jdbc-h2/src/main/resources/migrations/h2/V1_16__log_timestamp_index.sql
new file mode 100644
index 0000000000..9ade9e9887
--- /dev/null
+++ b/jdbc-h2/src/main/resources/migrations/h2/V1_16__log_timestamp_index.sql
@@ -0,0 +1,1 @@
+CREATE INDEX IF NOT EXISTS logs_timestamp ON logs ("timestamp");
\ No newline at end of file
diff --git a/jdbc-mysql/src/main/resources/migrations/mysql/V1_16__log_timestamp_index.sql b/jdbc-mysql/src/main/resources/migrations/mysql/V1_16__log_timestamp_index.sql
new file mode 100644
index 0000000000..1524f846c1
--- /dev/null
+++ b/jdbc-mysql/src/main/resources/migrations/mysql/V1_16__log_timestamp_index.sql
@@ -0,0 +1,1 @@
+CREATE INDEX ix_timestamp ON logs (`timestamp`);
\ No newline at end of file
diff --git a/jdbc-postgres/src/main/resources/migrations/postgres/V1_16__log_timestamp_index.sql b/jdbc-postgres/src/main/resources/migrations/postgres/V1_16__log_timestamp_index.sql
new file mode 100644
index 0000000000..9ade9e9887
--- /dev/null
+++ b/jdbc-postgres/src/main/resources/migrations/postgres/V1_16__log_timestamp_index.sql
@@ -0,0 +1,1 @@
+CREATE INDEX IF NOT EXISTS logs_timestamp ON logs ("timestamp");
\ No newline at end of file
