tst_QMenu::overrideMenuAction() remove setActiveWindow()

2f6fe3a268 as made calls to
QApplicationPrivate::setActiveWindow() redundant.

Remove redundant calls.

Task-number: QTBUG-121488
Change-Id: Ib454d716d43f42309b141dd09f2dcd90b5f76740
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>

tests/auto/widgets/widgets/qmenu/tst_qmenu.cpp

@@ -531,7 +531,6 @@ void tst_QMenu::overrideMenuAction()
     m->addAction(aQuit);
 
     w.show();
-    QApplicationPrivate::setActiveWindow(&w);
     w.setFocus();
     QVERIFY(QTest::qWaitForWindowActive(&w));
     QVERIFY(w.hasFocus());