fix: use proper shulker box fallback model (fixes #283)

Author: oddlama

vane-trifles/src/main/resources/resource_pack/assets/minecraft/items/shulker_box.json

@@ -3,9 +3,13 @@
     "type": "range_dispatch",
     "property": "minecraft:custom_model_data",
     "fallback": {
-      "type": "minecraft:shulker_box",
-      "texture": "minecraft:shulker"
-    }
+      "type": "minecraft:special",
+      "base": "minecraft:item/shulker_box",
+      "model": {
+        "type": "minecraft:shulker_box",
+        "texture": "minecraft:shulker"
+      }
+    },
     "entries": [
       {
         "threshold": 7733271,