tst_QGraphicsProxyWidget::mapToGloval() remove setActiveWindow()

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

Remove redundant calls.

Task-number: QTBUG-121488
Change-Id: Ib5f081fb03e3abd8cb8492a6d673ade98762e26a
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>

tests/auto/widgets/graphicsview/qgraphicsproxywidget/tst_qgraphicsproxywidget.cpp

@@ -3530,7 +3530,6 @@ void tst_QGraphicsProxyWidget::mapToGlobal() // QTBUG-41135
     childWidget->resize(embeddedWidget->size() / 2);
     childWidget->move(embeddedWidget->width() / 4, embeddedWidget->height() / 4); // center in embeddedWidget
     scene.addWidget(embeddedWidget);
-    QApplicationPrivate::setActiveWindow(&view);
     view.show();
     QVERIFY(QTest::qWaitForWindowExposed(&view));
     const QPoint embeddedCenter = embeddedWidget->rect().center();