tst_QGraphicsView::QTBUG_70255_scrollTo() remove setActiveWindow()

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

Remove redundant calls.

Task-number: QTBUG-121488
Change-Id: If78234df30ca5716bd8bb23eb4297ae461ae88a8
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>

tests/auto/widgets/graphicsview/qgraphicsview/tst_qgraphicsview.cpp

@@ -4962,7 +4962,6 @@ void tst_QGraphicsView::QTBUG_70255_scrollTo()
     view.centerOn(0, 0);
 
     view.show();
-    QApplicationPrivate::setActiveWindow(&view);
     if (!QTest::qWaitForWindowExposed(&view) || !QTest::qWaitForWindowActive(&view))
         QSKIP("Failed to show and activate window");