We always create /System/Library/LaunchDaemons/ when building the WebKit Xcode project, but not all builds need the directory.
<rdar://96013133>
Pull request: https://github.com/WebKit/WebKit/pull/1866
Committed 251969@main (d0b2da359950): <https://commits.webkit.org/251969@main> Reviewed commits have been landed. Closing PR #1866 and removing active labels.