improve sysmenu behavior

Zhao Yuhang

2024-05-07 357532958f2e806c69c96f018333a45e65e35201

 src/core/contexts/abstractwindowcontext.cpp

@@ -260,6 +260,12 @@
                m_windowAttributes.insert(it.key(), it.value());
            }
        }

        // Send to shared dispatchers
        if (oldWinId != m_windowId) {
            QEvent e(QEvent::WinIdChange);
            sharedDispatch(m_host, &e);
        }
    }

    QVariant AbstractWindowContext::windowAttribute(const QString &key) const {