Remove old GNOME workaround repo, add KDE F33 backgrounds one
    
    Add a workaround repo to kde.ks to get the kde-settings that
    will put F33 backgrounds in F33 images (hopefully). Remove an old
    workaround repo from the desktop kickstarts that isn't needed
    any more.
    
    Signed-off-by: Adam Williamson <awilliam@redhat.com>