[glib] (6 commits) ...Merge branch 'wip/smcv/deprecated-prop-followup' into 'main'

[Philip Withnall <pwithnall src gnome org>]

Summary of changes:

  88e160d... tests: Move common test environment variables to top level (*)
  25d21ed... gio/tests: Disable deprecation warnings where necessary (*)
  0bba27e... gobject/tests: Exercise a floating object reaching last-unr (*)
  7254fd7... gobject/tests: Don't unref a floating object reference by m (*)
  831f5c5... tests: Run all tests with deprecated property warnings enab (*)
  4bc284f... Merge branch 'wip/smcv/deprecated-prop-followup' into 'main

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