Fix memory leak by properly detaching model finalizer (#9979)

When unloading models in load_models_gpu(), the model finalizer was not
being explicitly detached, leading to a memory leak. This caused
linear memory consumption increase over time as models are repeatedly
loaded and unloaded.

This change prevents orphaned finalizer references from accumulating in
memory during model switching operations.

comfy/model_management.py

@@ -645,7 +645,9 @@ def load_models_gpu(models, memory_required=0, force_patch_weights=False, minimu
             if loaded_model.model.is_clone(current_loaded_models[i].model):
                 to_unload = [i] + to_unload
         for i in to_unload:
-            current_loaded_models.pop(i).model.detach(unpatch_all=False)
+            model_to_unload = current_loaded_models.pop(i)
+            model_to_unload.model.detach(unpatch_all=False)
+            model_to_unload.model_finalizer.detach()
 
     total_memory_required = {}
     for loaded_model in models_to_load: