Minecraft wiki entry for Development_versions, associated text: Added Soul Speed enchantment.
A new treasure enchantment only obtainable via bartering with piglins.
Only available on boots.
Allows faster walking on soul sand and soul soil.
There is a 4% chance that the durability of the boots goes down for each soul sand or soul soil block stepped on.
Cannot be obtained from enchanting tables, fishing, or trading. However, can be found in chest loot in this snapshot due to a bug.[15]