fix: define model_version so load_tokenizer resolves it

config.json

@@ -1,4 +1,5 @@
 {
+  "model_version": null,
   "add_classification_head": false,
   "anyres_pooling_size": 2,
   "anyres_vit_max_image_size": null,
@@ -4771,4 +4772,4 @@
   "vit_used_rms_norm": false,
   "vocab_size": 133120,
   "xdrope_section": null
-}
+}