Assign user_id if not present in key/generate

If the user_id is not specified in the key/generate request it is not added automatically and doesn't appear in the dashboard.

litellm/proxy/management_endpoints/key_management_endpoints.py

@@ -580,6 +580,9 @@ async def _common_key_generation_helper(  # noqa: PLR0915
         prisma_client=prisma_client,
     )
 
+    if data_json.get("user_id", None) is None:
+        data_json["user_id"] = user_api_key_dict.user_id
+
     await _enforce_unique_key_alias(
         key_alias=data_json.get("key_alias", None),
         prisma_client=prisma_client,