[vala] (5 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:

  60cdcab... vala: Enforce required type-arguments on parameter/return t
  7d74505... glib-2.0,gio-2.0,gobject-2.0: Update 2.74 symbols
  ef81782... gstreamer: Update from 1.21.0+ git main
  b61335f... vapi: Update GIR-based bindings
  2511f75... atspi-2: Fix a few binding errors

Commits added to the branch:

  661f08e... vala: Enforce required type-arguments on parameter/return t
  7217373... glib-2.0,gio-2.0,gobject-2.0: Update 2.74 symbols
  9326345... gstreamer: Update from 1.21.0+ git main
  03725ca... vapi: Update GIR-based bindings
  edd3389... atspi-2: Fix a few binding errors