After a few weeks of work: a #GNOME session running on the #shepherd!

This implementation in #guile is completely independent of systemd and can run on any init system!

Thanks to @AdrianVovk for their help 😀

#Guix will need this for GNOME 49, since the original GNOME session dropped the non-systemd implementation. Source code at gitlab.gnome.org/noe/gnome-ses…