Fix type hint

fastapi/openapi/utils.py

@@ -193,7 +193,7 @@ def get_openapi_path(
     *, route: routing.APIRoute, model_name_map: Dict[type, str], operation_ids: Set[str]
 ) -> Tuple[Dict[str, Any], Dict[str, Any], Dict[str, Any]]:
     path = {}
-    empty_responses: List[int] = []
+    empty_responses: List[str] = []
     security_schemes: Dict[str, Any] = {}
     definitions: Dict[str, Any] = {}
     assert route.methods is not None, "Methods must be a list"
@@ -308,7 +308,7 @@ def get_openapi_path(
                         process_response, dict
                     ), "An additional response must be a dict"
                     if not process_response and not process_rseponse_model:
-                        empty_responses.append(additional_status_code)
+                        empty_responses.append(str(additional_status_code))
                     field = route.response_fields.get(additional_status_code)
                     additional_field_schema: Optional[Dict[str, Any]] = None
                     if field:
@@ -359,7 +359,7 @@ def get_openapi_path(
                 deep_dict_update(operation, route.openapi_extra)
             if empty_responses:
                 for response_status_code in empty_responses:
-                    del operation["responses"][str(response_status_code)]
+                    del operation["responses"][response_status_code]
             path[method.lower()] = operation
     return path, security_schemes, definitions