dev: switch to stonecutter build system

- This will allow us to build the library for different Minecraft versions at the same time
- Right now, only Fabric and Neoforge 1.21.10 are fully working
- As a bonus, the jar is now even smaller!

versions/1.21.5-neoforge/gradle.properties

@@ -0,0 +1,12 @@
+mod.mc_dep_fabric==1.21.5
+mod.mc_dep_forgelike=[1.21.5]
+mod.mc_title=1.21.5
+mod.mc_targets=1.21.5
+
+deps.forge_loader=0
+deps.neoforge_loader=21.5.54-beta
+
+deps.fabric_version=0.121.0+1.21.5
+deps.modmenu_version=[UNSUPPORTED]
+
+loom.platform=neoforge