tst_QAbstractItemView::testChangeEditorState() remove setActiveWindow()

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

Remove redundant calls.

Task-number: QTBUG-121488
Change-Id: I5756f3298225a3d7564ff65e9c72c263f5903370
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>

tests/auto/widgets/itemviews/qabstractitemview/tst_qabstractitemview.cpp

@@ -1704,7 +1704,6 @@ void tst_QAbstractItemView::testChangeEditorState()
     centerOnScreen(&view);
     moveCursorAway(&view);
     view.show();
-    QApplicationPrivate::setActiveWindow(&view);
     QVERIFY(QTest::qWaitForWindowActive(&view));
     QCOMPARE(&view, QApplication::activeWindow());