Add mypy error codes to '# type: ignore' comments (#6379)

stdlib/http/cookies.pyi

@@ -29,7 +29,7 @@ class Morsel(Dict[str, Any], Generic[_T]):
         def set(self, key: str, val: str, coded_val: _T, LegalChars: str = ...) -> None: ...
     def setdefault(self, key: str, val: str | None = ...) -> str: ...
     # The dict update can also get a keywords argument so this is incompatible
-    @overload  # type: ignore
+    @overload  # type: ignore[override]
     def update(self, values: Mapping[str, str]) -> None: ...
     @overload
     def update(self, values: Iterable[tuple[str, str]]) -> None: ...