quickwindowagent: Remove const for HitTestVisible API.

Dylan Liu

2024-05-30 ef7c04cd9ac06b64c516db47bda6f4d9c12db3b9

 examples/mainwindow/mainwindow.cpp

@@ -60,8 +60,7 @@
    setWindowTitle(tr("Example MainWindow"));
    resize(800, 600);

    setFixedHeight(600);

    // setFixedHeight(600);
    // windowAgent->centralize();
}