ci: drop quarantine removal for macos perforce binaries

A file downloaded with wget never gets com.apple.quarantine set, only Safari, Finder, and AirDrop apply that attribute through the LaunchServices quarantine API.

5ed9fc3f (ci: prevent perforce from being quarantined, 2020-02-27) added this to stop p4d -V from hanging on a GUI confirmation dialog that never comes on a CI box, back when perforce was installed via Homebrew's --no-quarantine cask flag. When 49af4481 (ci: reintroduce prevention from perforce being quarantined in macOS, 2022-05-12) replaced that with a plain wget and tar download, it kept an xattr -d call as a precaution while noting that call already does nothing on GitHub Actions. It has been a silent no-op ever since.

Signed-off-by: Harald Nordgren haraldnordgren@gmail.com