[PATCH] wallpapers/image: Fix thumbnails not matching output size

[PATCH] wallpapers/image: Fix thumbnails not matching output size

The `Screen` is an attached property and it never changes, we need to
monitor screen size changes instead.

BUG: 483097

(cherry picked from commit d6436e077c05abd100d905aaa73222a48ca1695f)

7678dfa9 wallpapers/image: Fix thumbnails not matching output size
5f4d8bc8 Apply 1 suggestion(s) to 1 file(s)

Co-authored-by: Vlad Zahorodnii <vlad.zahorodnii@kde.org>
Gbp-Pq: Name upstream_6d12cde3_wallpapers-image-Fix-thumbnails-not-matching-output-size.patch