Fix ghosts following a moving entity causing them to be offset (#22783)

Fix ghosts following a moving entity causing them to be offset (#22783)

Fixes #14220

Because the entity they start following is moving, the physics system gives the follower opposing velocity to counteract, at the time the parent change happens. This happens *after* the follower system tries to clear the follower's velocity, so the follower gets some velocity that will still move them a bit off-center.

Fix is easy enough, just reset velocity *after* reparenting, not before.