Currently we assume `self._filesystem.glob(self._webkit_baseline_path("*"))` gives us all baseline paths, but this isn't actually true (e.g., additional_platform_directory).
Pull request: https://github.com/WebKit/WebKit/pull/6814
<rdar://problem/102901454>
Committed 257480@main (008f6b91afed): <https://commits.webkit.org/257480@main> Reviewed commits have been landed. Closing PR #6814 and removing active labels.