3D Skin Layers

Changes

• Fixed 1.16.5 not running with Java 8
• Updated the German language file
• More build system fixes (I hope I don't have to manually edit the 40 files title again)
• (forgot to mention in 1.6.0: the mod id everywhere is now "skinlayers3d", even on fabric)

Note: Some mods interfacing with 3d skin layers like [ETF] Entity Texture Features will require an update to work again with 1.6.0+. If you need ETF or other mods that got broken by the update, use the old version until they have time to update for the new release.