Merge branch 'non-registered-extension-point' into 'main'

Add missing extension point register for various settings backends

See merge request GNOME/glib!2813

gio/tests/meson.build

@@ -87,10 +87,12 @@ gio_tests = {
   'memory-input-stream' : {},
   'memory-monitor' : {},
   'memory-output-stream' : {},
+  'memory-settings-backend' : {},
   'mount-operation' : {},
   'network-address' : {'extra_sources': ['mock-resolver.c']},
   'network-monitor' : {},
   'network-monitor-race' : {},
+  'null-settings-backend' : {},
   'permission' : {},
   'pollable' : {'dependencies' : [libutil_dep]},
   'power-profile-monitor' : {},