main: Replace Meta.register_with_session()

The functionality moved into the new Meta.Context.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1917>

js/ui/main.js

@@ -258,7 +258,7 @@ function _initializeUI() {
     // We're ready for the session manager to move to the next phase
     GLib.idle_add(GLib.PRIORITY_DEFAULT, () => {
         Shell.util_sd_notify();
-        Meta.register_with_session();
+        global.context.notify_ready();
         return GLib.SOURCE_REMOVE;
     });