When teleporting a mounted entity, it becomes dismounted. This breaks a very large amount of interactions that datapack creators utilize and was not present in previous versions.

Steps to reproduce:

1. Run the following summon command:

/summon husk ~ ~ ~ {Tags:["bottom"],Passengers:[{id:"minecraft:husk",Tags:["top"]}]}

2. Run the following tp command:

/execute as @n[tag=top] at @s run tp @s ~ ~10 ~

3. Observe in 1.21 and then latest snapshot. In version 1.21 the entities do NOT dismount. However, in the latest snapshot this dismounts the entities.

Expected outcome:

The entity that is mounted should not dismount