kcms/icons: use `MatchBestOrGreaterSize` to get expected icons
The icon KCM needs to filter out small icons in previews because adwaita-icon-theme removed many 32x32 pixmaps.
Depends on frameworks/kiconthemes!93 (merged)
Ref: https://gitlab.gnome.org/GNOME/adwaita-icon-theme/-/commit/74aa69851dd37b863eb071fae4c2365f5bc04030