[Cocoa] We're unnecessarily asking the system whether fonts we created are the system font or not
<rdar://problem/105442047>
Pull request: https://github.com/WebKit/WebKit/pull/10081
Committed 260289@main (ad421fc347f6): <https://commits.webkit.org/260289@main> Reviewed commits have been landed. Closing PR #10081 and removing active labels.