Update pack format to align with Minecraft 1.19 (#80)

* Update pack format to align with Minecraft 1.19

This uses the resource pack format for 1.19, rather than the data pack
format which is currently 10 for 1.19.

* Use Forge-specific pack format keys

This allows Forge environments to apply the proper pack format when the
pack is loaded as either a resource pack or a data pack.

As MC is lenient on additional keys, this does not break Fabric/other
environments.

Author: sciwhiz12

Common/src/main/resources/pack.mcmeta

@@ -1,6 +1,8 @@
 {
   "pack": {
     "description": "${mod_description}",
-    "pack_format": 8
+    "pack_format": 9,
+    "forge:resource_pack_format": 9,
+    "forge:data_pack_format": 10
   }
 }