Tst_QGestureRecognizer::panGesture set FramelessWindowHint

tst_QGestureRecognizer::panGesture() is flaky as sometimes the gesture
event is being sent before the frame and position has had time to
update. The event then starts in the frame and is not received by the
widget.

Set FramelessWindowHint flag to the widget, to remove the need of
updating its frame position and position.

Fix flakiness on Opensuse 15

Pick-to: 6.5
Change-Id: Id88510a91e3ed0d5ff92fdc31422503744448b3e
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>
(cherry picked from commit fc0e788d029beac251fda40650154fc6865e1649)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
(cherry picked from commit ea55328741c6a1aceb7b1a456c00d976be940a42)

tests/auto/widgets/kernel/qgesturerecognizer/tst_qgesturerecognizer.cpp

@@ -158,6 +158,7 @@ void tst_QGestureRecognizer::panGesture()
     const Qt::GestureType gestureType = Qt::PanGesture;
     TestWidget widget(GestureTypeVector(1, gestureType));
     widget.setWindowTitle(QTest::currentTestFunction());
+    widget.setWindowFlag(Qt::FramelessWindowHint);
     widget.show();
     QVERIFY(QTest::qWaitForWindowExposed(&widget));