[vala] (3 commits) Non-fast-forward update to branch staging

[Rico Tzschichholz <ricotz src gnome org>]

The branch 'staging' 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:

  f759315... glib-2.0: Add `double_hash` and `double_equal`
  00233c5... gtk4: Make Gtk.show_uri_full() an instance method of Gtk.Wi
  f91b1f8... tests: Add "entry point exists" test to increase coverage

Commits added to the branch:

  c6d4ee9... glib-2.0: Add `double_hash` and `double_equal`
  cf54db5... gtk4: Make Gtk.show_uri_full() an instance method of Gtk.Wi
  9c8a449... tests: Add "entry point exists" test to increase coverage