Static AVIF images have the image type "public.avif". This was added to the list of supported image formats in bug 241904. We need also to add the image type of the animated AVIF image which is "public.avis".
<rdar://problem/97757110>
Pull request: https://github.com/WebKit/WebKit/pull/2836
Committed 253002@main (7cb2a0410253): <https://commits.webkit.org/253002@main> Reviewed commits have been landed. Closing PR #2836 and removing active labels.