Unpatch assemblies when exiting playmode when user has domain reload disabled

If tool hot-reloaded assemblies in playmode and user has domain reload disabled - those changes will persist into editor mode and won't be cleaned up on next play-mode entry.

It'd be best to simply unpatch when exiting playmode

No files, tests, or entry points are named. Start by locating the Unity play-mode exit handling and the assembly patching flow; verify how domain reload disabled affects cleanup. Done means assemblies hot-reloaded during playmode are unpatched when exiting playmode and do not persist into the editor or the next play-mode entry.

索引モデルが issue の本文から書いたものです。