chore: revert "fix: Raising an error message to the user when registering an existing provider." (#3750)

Reverts llamastack/llama-stack#3624
Causing https://github.com/llamastack/llama-stack/issues/3749

llama_stack/core/store/registry.py

@@ -98,10 +98,7 @@ class DiskDistributionRegistry(DistributionRegistry):
         existing_obj = await self.get(obj.type, obj.identifier)
         # dont register if the object's providerid already exists
         if existing_obj and existing_obj.provider_id == obj.provider_id:
-            raise ValueError(
-                f"Provider '{obj.provider_id}' is already registered."
-                f"Unregister the existing provider first before registering it again."
-            )
+            return False
 
         await self.kvstore.set(
             KEY_FORMAT.format(type=obj.type, identifier=obj.identifier),

tests/unit/registry/test_registry.py

@@ -125,15 +125,8 @@ async def test_duplicate_provider_registration(cached_disk_dist_registry):
         provider_resource_id="test_vector_db_2",
         provider_id="baz",  # Same provider_id
     )
+    await cached_disk_dist_registry.register(duplicate_vector_db)
 
-    # Now we expect a ValueError to be raised for duplicate registration
-    with pytest.raises(
-        ValueError,
-        match=r"Provider 'baz' is already registered.*Unregister the existing provider first before registering it again.",
-    ):
-        await cached_disk_dist_registry.register(duplicate_vector_db)
-
-    # Verify the original registration is still intact
     result = await cached_disk_dist_registry.get("vector_db", "test_vector_db_2")
     assert result is not None
     assert result.embedding_model == original_vector_db.embedding_model  # Original values preserved