kimageformats backport request

[Nate Graham]

Hello distro packagers!

I would recommend backporting the following commits to your 
kimageformats packaging:

- 
https://invent.kde.org/frameworks/kimageformats/-/commit/350ce1b990460cb2178f369f22fe80803f5645f3
- 
https://invent.kde.org/frameworks/kimageformats/-/commit/1190e53e9b69da6f9663ceb75c4813c5708b7cbd

These commits fix a significant performance issue experienced when using 
animated AVIF images.

Thanks!

Nate