fix: QObjectPrivate::threadData type change when qt >=5.15

iveswang

2024-06-12 7610c3a509b8a04d25e72a6282d9c8ea8ecbd27f

 examples/mainwindow/mainwindow.cpp

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

    setFixedHeight(600);

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