[mutter] (2 commits) Non-fast-forward update to branch bilelmoussaoui/make-canberra-a-plugin

[Bilal Elmoussaoui <bilelmoussaoui src gnome org>]

The branch 'bilelmoussaoui/make-canberra-a-plugin' 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:

  9d547b7... Core: Make sound player feature optional

Commits added to the branch:

  7d3ff66... clutter/stage: Remove unused nullable annotation (*)
  9d0d12a... core: Make sound player feature optional

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