Update mutter to version 42.4 / rev 188 via SR 994795
    
    https://build.opensuse.org/request/show/994795
    by user dimstar + dimstar_suse
    - Update to version 42.4:
      + screencast: Set correct stride when using dmabufs
      + Fix glitches in apps using subsurfaces
      + Reduce client work when entering overview
      + Highlight actors becoming reactive under the pointer
      + Fall back to ARGB if XRGB is not supported
      + Support direct scanout on GPUs without modifiers support
      + Fix registering as X11 window manager if GDK_BACKEND is set
      + Fixed crash
      + Plugged leak
      + Misc. bug fixes and cleanups. (forwarded request 994625 from iznogood)