Entity cannot move the Warden

Summary:
Player or other mobs cannot move the Warden with their hitbox. This does not match the java version where the Warden can be moved.

Steps to reproduce:

1. Summon a Warden.
2. Try to move it with your hitbox.

Observed results:
Warden is immune to other hitboxes, so he can't be moved.

Expected results:
Warden will be susceptible to hitboxes from other entities and can be moved.