## About The Pull Request
Fixes#77041
Getting onto someone's back would give you "TRAIT_UNDENSE" to stop you
from colliding with things your mount could cross.
Getting off someone's back would remove "TRAIT_UNDENSE" from the person
being ridden.
They didn't have the trait, so removing it from them wasn't very useful.
## Why It's Good For The Game
This is silly
## Changelog
🆑
fix: Dismounting from a piggyback no longer allows you to phase through
other players.
/🆑
c2693ef65e