Totally fix top border issue on Win10 for QtWidgets

Sine Striker

2023-12-26 6b2d31247dc2c2804e571b31a71c8a423c1db9d4

 examples/mainwindow/mainwindow.cpp

@@ -115,10 +115,6 @@
    windowAgent = new QWK::WidgetWindowAgent(this);
    windowAgent->setup(this);

#ifdef Q_OS_WIN
    windowAgent->setWindowAttribute(QStringLiteral("dark-mode"), true);
#endif

    // 2. Construct your title bar
    auto menuBar = [this]() {
        auto menuBar = new QMenuBar();