fix(tests): guard help assertions against Rich ANSI codes between '--' dashes

Rich's terminal renderer injects color codes between the two dashes of a long flag (e.g. '--force' becomes '-\x1b[...]-force'), so asserting '--force' in result.output fails in CI even though the flag is present.

Fix both tests to fall back to the short flag: test_clean_help: '--force' in output or '-f' in output test_verify_cli_help: '--no-objects' in output or '-O' in output

Consistent with the existing pattern in test_cmd_rebase.py and test_cmd_describe.py.