js: Set BoxLayout orientation

Use new `orientation` property instead of `vertical`.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/3614>

js/ui/osdWindow.js

@@ -34,7 +34,7 @@ class OsdWindow extends Clutter.Actor {
         this._hbox.add_child(this._icon);
 
         this._vbox = new St.BoxLayout({
-            vertical: true,
+            orientation: Clutter.Orientation.VERTICAL,
             y_align: Clutter.ActorAlign.CENTER,
         });
         this._hbox.add_child(this._vbox);