Add support for other image formats (.jxl .heif)

Flatpak Gradia v1.13.0 
OS: Fedora Linux 43.20260812.0 (COSMIC Atomic) x86_64

Please could open/save support for .jxl & .heif be added?

Currently if to annotate a photo a took on iPhone (.heif), or image that needs to be in a format like .jxl or post annotation you have to use multiple apps, convert pre/post annotation. Or use sledge hammer that is GIMP ...

Thanks,