Since we are pushing for HF repos, we should accept them in inference configs (#497)

# What does this PR do?

As the title says. 

## Test Plan

This needs
8752149f58
to also land. So the next package (0.0.54) will make this work properly.

The test is:

```bash
pytest -v -s -m "llama_3b and meta_reference" test_model_registration.py
```

llama_stack/providers/utils/inference/__init__.py

@@ -22,9 +22,9 @@ def is_supported_safety_model(model: Model) -> bool:
     ]
 
 
-def supported_inference_models() -> List[str]:
+def supported_inference_models() -> List[Model]:
     return [
-        m.descriptor()
+        m
         for m in all_registered_models()
         if (
             m.model_family in {ModelFamily.llama3_1, ModelFamily.llama3_2}