Add AVIF

[JanisPlayer]

I'm currently making a change to Nextcloud that allows for the creation of JPEG previews from AVIF images.
With this change, if the proposal is accepted, this app would also be up-to-date.
But there's still one question that needs to be answered: How good is the browser support for AVIF? Can it be added to the well-supported formats without Edge's support, or not?
The browser support for AVIF has greatly improved. Only Edge, Opera Mini, QQ Browser, KaiOS Browser, and of course IE don't support it anymore.

[skjnldsv]

83.35% support is a bit low to my taste 🤔

[github-actions]

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