Update the window geometry when changing decorations

Windows' geometries should be updated when changing decorations.

Fixes: QTBUG-100467
Pick-to: 6.3 6.2 5.15
Change-Id: I5ec9968aa48422776d184a8fa2f5d86ecc3ca5c3
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>
Reviewed-by: Liang Qi <liang.qi@qt.io>

src/plugins/platforms/wayland/qwaylandwindow.cpp

@@ -952,7 +952,7 @@ bool QWaylandWindow::createDecoration()
             QMargins m = frameMargins();
             subsurf->set_position(pos.x() + m.left(), pos.y() + m.top());
         }
-        sendExposeEvent(QRect(QPoint(), geometry().size()));
+        setGeometry(geometry());
 
         // This is a special case where the buffer is recreated, but since
         // the content rect remains the same, the widgets remain the same