Copper Age Backport

[1.21.1-0.0.5-hotfix1] - 2025-11-20

Fixed

• Tag Loading Error: Fixed "missing references" error for optional mod chests
  • Issue: Tag loading failed when IronChest mod were not installed
  • Error: Couldn't load tag coppergolemlegacy:golem_target_chests as it is missing following references
  • Solution: Changed all optional mod entries to use {"id": "...", "required": false} format
  • Affected mods: IronChest (14 chest types)
  • Mod now works properly both with and without IronChest installed