I tested eog version 3.36.2-0ubuntu1 from focal-proposed: I can confirm that this version fixes the problem. I can now open HEIF/HEIC files again. Opening JPEG and PNG files also still works.
I tested eog version 3.36.2-0ubuntu1 from focal-proposed:
I can confirm that this version fixes the problem. I can now open HEIF/HEIC files again. Opening JPEG and PNG files also still works.