tests: XFAIL tst_QScreen::grabWindow() on Wayland

Task-number: QTBUG-100792
Pick-to: 6.3 6.2
Change-Id: I1dc257abdc34c586c4c1eda96a43ea75395b1e4a
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

tests/auto/gui/kernel/qscreen/tst_qscreen.cpp

@@ -302,6 +302,8 @@ void tst_QScreen::grabWindow()
 
     QImage grabbedImage = pixmap.toImage();
     const QSize grabbedSize = grabbedImage.size();
+    if (QGuiApplication::platformName().startsWith(QLatin1String("wayland"), Qt::CaseInsensitive))
+        QEXPECT_FAIL("", "Wayland: Screen grabbing not implemented, See QTBUG-100792.", Abort);
     QCOMPARE(grabbedSize, expectedGrabSize);
 
     QPoint pixelOffset = QPoint(0, 0);