Mobs in boats and minecarts can change their leg positions for a second when they take damage

Summary:
Mobs in boats and minecarts can change their leg positions for a second when they take damage. This happened after fixing a bug where mobs didn't have hurt animations.

Steps to reproduce:

1. Put the mob in the boat or minecart.
2. Hit the mob multiple times.

Observed results:
Mobs in the boat or minecart move their legs for a second, as if they were hit.

Expected results:
The legs of the mobs will be motionless in the boat and minecart.

Video:
Minecraft Preview 2022-07-28 22-50-06.mp4

Screenshot: