[retro-gtk] (6 commits) Non-fast-forward update to branch stable-api

[Adrien Plazas <aplazas src gnome org>]

The branch 'stable-api' was changed in a way that was not a fast-forward update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  ac8ad90... Drop the RETRO_GTK_USE_UNSTABLE_API guard

Commits added to the branch:

  1736b0a... Add and use GL autocleanup (*)
  a48a496... ipc: Add and use retro_try_propagate_dbus() (*)
  f71c48a... meson: Add gio_unix to retro-gtk/meson.build (*)
  1acc7dc... meson: Bump API version to 2 (*)
  7fcd160... Initial GTK4 port (*)
  7a476b7... Drop the RETRO_GTK_USE_UNSTABLE_API guard

(*) This commit already existed in another branch; no separate mail sent