JPEG XL was temporarily disabled on older OSes until we get bug 259587 fixed.
rdar://117049172
Pull request: https://github.com/WebKit/WebKit/pull/19519
Committed 269900@main (5fb255b53fc5): <https://commits.webkit.org/269900@main> Reviewed commits have been landed. Closing PR #19519 and removing active labels.
Committed 269962@main (9d3f5bce8bc6): <https://commits.webkit.org/269962@main> Reviewed commits have been landed. Closing PR #19727 and removing active labels.