Avian Integration 0.2.0 - 2024-12-21

Changed

• Upgrade to Bevy 0.15 and avian 0.2.

Removed

• TnuaAvian#dPlugin no longer implements Default. Since Avian changed their
  default schedule from PostUpdate to FixedPostUpdate, user code that just
  uses the de-facto default Update will start having weird results. This
  forces the user to make a deliberate decision regarding which schedule to run.