Fixes

build.gradle.kts

···
         dependsOn(datapack)
     }
 
-    tasks.withType<GenerateModJsonJarsEntry> {
-        val fabric119RemapJar: RemapJar by tasks
-        val fabric121RemapJar: RemapJar by tasks
-        jar.set(fabric119RemapJar.archiveFile)
-        jar.set(fabric121RemapJar.archiveFile)
-    }
-
     val datapackZip by tasks.registering(Zip::class) {
         from(cloche.common("common:datapack").sourceSet.output.resourcesDir!!) {
             include("data/**")

src/fabric/1.21/main/java/xyz/naomieow/ibo/IboMod.java

···
 import net.fabricmc.fabric.api.resource.ResourceManagerHelper;
 import net.fabricmc.fabric.api.resource.ResourcePackActivationType;
 import net.fabricmc.loader.api.FabricLoader;
+import net.minecraft.network.chat.Component;
 import net.minecraft.resources.ResourceLocation;
 
 public class IboMod implements ModInitializer {
     @Override
     public void onInitialize() {
-        FabricLoader.getInstance().getModContainer("xyz/naomieow/ibo").ifPresent((modContainer ->
-            ResourceManagerHelper.registerBuiltinResourcePack(
-                ResourceLocation.tryBuild("xyz/naomieow/ibo", "xyz/naomieow/ibo"),
-                modContainer,
-                "Incendium Biomes Only",
+        ResourceManagerHelper.registerBuiltinResourcePack(
+                ResourceLocation.tryBuild("ibo", "ibo"),
+                FabricLoader.getInstance().getModContainer("ibo").get(),
+                Component.literal("Incendium Biomes Only"),
                 ResourcePackActivationType.ALWAYS_ENABLED
-            )
-        ));
+        );
     }
 }