QScreen::size is wrong on GNOME Wayland with 200% scaling

GNOME seem to have a special reading of the xdg-output protocol and provides screen pixel size not divided by scale factor unlike all other compositors. To make this even more complicated, they change the behavior to the common one once scale-monitor-framebuffer experimental feature (Ubuntu patches the settings application to present it as fractional scaling option in monitor settings) is enabled. mutter folks seem to defend their reading of the protocol and gtk has fixed this by comparing xdg_output size with wl_output size and dividing the size by scale factor if it's the same.

https://gitlab.gnome.org/GNOME/mutter/-/issues/2631
https://gitlab.gnome.org/GNOME/gtk/-/merge_requests/6832