Allow dimensions to be removed

Fixes neoforged/NeoForge#102

Author: embeddedt

forge/src/main/java/org/embeddedt/modernfix/forge/mixin/bugfix/removed_dimensions/LevelStorageSourceMixin.java

@@ -0,0 +1,14 @@
+package org.embeddedt.modernfix.forge.mixin.bugfix.removed_dimensions;
+
+import net.minecraft.world.level.storage.LevelStorageSource;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.ModifyArg;
+
+@Mixin(LevelStorageSource.class)
+public class LevelStorageSourceMixin {
+    @ModifyArg(method = "*", at = @At(value = "INVOKE", target = "Lcom/mojang/serialization/DataResult;getOrThrow(ZLjava/util/function/Consumer;)Ljava/lang/Object;", ordinal = 0), index = 0)
+    private static boolean alwaysAllowPartialDimensions(boolean flag) {
+        return true;
+    }
+}