The test is very flaky on Windows 11. Make sure that we have a secondary
window to close before proceeding, and wait for fade effects to finish,
otherwise we might never get the leave event from the windowing system.
Also replace a QVERIFY(qWaitFor) construct with a simple QTRY_VERIFY.
With these changes, a local run of 20 repeats of this test on a stressed
VM improves from 75% to 100%.
Pick-to: 6.3 6.2
Fixes: QTBUG-98477
Change-Id: Iedcc175b336e3cab23817b954aba1736d02f1b9d
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Heikki Halmet <heikki.halmet@qt.io>
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>
3fbe201d21