test_update_cli: also test --help

pkgs/clan-cli/clan_cli/update.py

@@ -94,7 +94,6 @@ def update(args: argparse.Namespace) -> None:
 
 
 def register_parser(parser: argparse.ArgumentParser) -> None:
-    parser.add_mutually_exclusive_group(required=True)
     # TODO pass all args we don't parse into ssh_args, currently it fails if arg starts with -
     parser.add_argument("--flake-uri", type=str, default=".#", help="nix flake uri")
     parser.add_argument(