fix(router): use string id in test_add_deployment and add defensive str() in register_model

- Change test to use string '100' instead of int 100 for model_info.id
- Add str() conversion in register_model to prevent AttributeError on non-string keys

Co-authored-by: Ishaan Jaff <ishaan-jaff@users.noreply.github.com>

litellm/utils.py

@@ -2765,8 +2765,9 @@ def register_model(model_cost: Union[str, dict]):  # noqa: PLR0915
     for key, value in loaded_model_cost.items():
         ## get model info ##
         provider = value.get("litellm_provider", "")
+        _key_str = str(key)
         if provider in _skip_get_model_info_providers or any(
-            key.startswith(f"{p}/") for p in _skip_get_model_info_providers
+            _key_str.startswith(f"{p}/") for p in _skip_get_model_info_providers
         ):
             existing_model = litellm.model_cost.get(key, {})
             model_cost_key = key

tests/router_unit_tests/test_router_helper_utils.py

@@ -807,7 +807,7 @@ def test_add_deployment(model_list):
     deployment = router.get_deployment_by_model_group_name(
         model_group_name="gpt-3.5-turbo"
     )
-    deployment["model_info"]["id"] = 100
+    deployment["model_info"]["id"] = "100"
     ## Test 1: call user facing function
     router.add_deployment(deployment=deployment)