Un-mixup the mixins.

This properly separates the forge and fabric mixins in the merged -mod jar.
By some miracle Forge was 'working' with the Fabric mixins, but this is probably safer overall.

worldedit-fabric/src/main/resources/fabric.mod.json

@@ -39,7 +39,7 @@
         "fabric-permissions-api-v0": "*"
     },
     "mixins": [
-        "worldedit.mixins.json"
+        "worldedit-fabric.mixins.json"
     ],
     "accessWidener" : "worldedit.accesswidener"
 }

worldedit-forge/src/main/resources/worldedit-forge.mixins.json

@@ -1,7 +1,7 @@
 {
     "required": true,
     "package": "com.sk89q.worldedit.forge.mixin",
-    "compatibilityLevel": "JAVA_17",
+    "compatibilityLevel": "JAVA_8",
     "mixins": [
         "MixinLevelChunkSetBlockHook"
     ],

worldedit-mod/build.gradle.kts

@@ -15,7 +15,7 @@
     from(zipTree({remapFabric.get().archiveFile}))
     from(zipTree({project(":worldedit-forge").tasks.getByName("shadowJar").outputs.files.singleFile}))
 
-    duplicatesStrategy = DuplicatesStrategy.EXCLUDE
+    duplicatesStrategy = DuplicatesStrategy.WARN
     archiveClassifier.set("dist")
 }