tst_QStylesheetStyle::hoverColors remove setActiveWindow()

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

Remove redundant calls.

Task-number: QTBUG-121488
Change-Id: I264c1703a0396356f6e17a3122b71bcb8f1813ad
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>

tests/auto/widgets/styles/qstylesheetstyle/tst_qstylesheetstyle.cpp

@@ -1025,7 +1025,6 @@ void tst_QStyleSheetStyle::hoverColors()
     QCursor::setPos(frame.geometry().topLeft() - QPoint(100, 0));
     frame.show();
 
-    QApplicationPrivate::setActiveWindow(&frame);
     QVERIFY(QTest::qWaitForWindowActive(&frame));
 
     QWindow *frameWindow = frame.windowHandle();