Bevy 0.12 upgrade

[nfagerlund]

Ok, I forgot whatever I was doing before the break, so, maybe this is a good time to get reacquainted with everything.

• [x] I assume my asset processor is gonna break.
  • https://bevyengine.org/learn/migration-guides/0.11-0.12/#bevy-asset-v2
  • https://bevyengine.org/news/bevy-0-12/
• [x] The tilemap libs are weirdly lagging on their upgrade releases this time around, probably because the maintainers are Le Tired, but anyway the work all appears to be done in branches and I'll need to do a cargo patch. https://github.com/Trouv/bevy_ecs_ldtk/pull/265
  • https://trouv.github.io/bevy_ecs_ldtk/latest/how-to-guides/migration-guides/migrate-from-0.8-to-0.9.html

[nfagerlund]

Uhhhhh cool, i guess we accomplished that!!

At first I thought there were some new problems with slime movement getting stuck or whatever, but it's just the patrol/aggro transitions getting into a wonky intersection briefly, and it existed previously.