Nest Egg

• fixed a compat-based crash when placing eggs into nests

• 1.21.1 port
• Addressing pre-emptive compat questions:
  • Adding compat to Spawn birds will prove difficult as they don't naturally strew their eggs all about (unlike turkeys and ducks). But maybe eventually?
  • NML geese don't actually lay eggs, so no compat is needed at this time

Fix startup crash when Bountiful Critters is installed

• fix crash with updated Naturalist and Bountiful Critters

• Added compat for Bountiful Critters pheasants/emus (thanks damikdevv for block textures!) and Environmental ducks.
• Downgraded Forge to maintain compat with NeoForge