[linter][prefer_const_constructors] miss opportunity

[stephane-archer]

class _FavoriteFoldersLoadingWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return const Center(
      child: CupertinoActivityIndicator(),
    );
  }
}

should suggest

class _FavoriteFoldersLoadingWidget extends StatelessWidget {

 const _FavoriteFoldersLoadingWidget();

  @override
  Widget build(BuildContext context) {
    return const Center(
      child: CupertinoActivityIndicator(),
    );
  }
}