when the flag AA_UseHighDpiPixmaps is set, the pixmap is already scaled,
no need to scale it twice.
the code calling virtual_hook in QIcon calls it with the following
ScaledPixmapArgument:
scalePixmapArg = { size * devicePixelRatio, mode, state, devicePixelRatio, QPixmap() }
The requested pixmap size is already scaled, counting devicePixelRatio
again will result in a pixmap scaled two times.