[libgd] (3 commits) Non-fast-forward update to branch wip/ernestask/gtk4

[Ernestas Kulik <ernestask src gnome org>]

The branch 'wip/ernestask/gtk4' 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:

  46e31a7... notification: use an event controller for motion events
  400ec89... notification: remove visibility_notify_event override
  6397ba3... notification: default to being invisible
  a4ec2a7... Remove GdNotification
  b2c278a... Revert "Remove GdNotification"

Commits added to the branch:

  e4a3268... notification: use an event controller for motion events
  c1b460b... notification: remove visibility_notify_event override
  5b2683b... notification: default to being invisible