sync: from linuxdeepin/qt5platform-plugins

[deepin-ci-robot]

Synchronize source files from linuxdeepin/qt5platform-plugins.

Source-pull-request: linuxdeepin/qt5platform-plugins#268

[deepin-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

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deepin pr auto review

关键摘要:

• cursorThemePropertyChanged 函数中的 Q_UNUSED 宏用于忽略未使用的参数，但应该明确注释说明为什么这些参数未使用。
• cursorThemePropertyChanged 函数中的 QMetaObject::invokeMethod 使用了 Qt::QueuedConnection，这可能会导致界面响应延迟，应该评估是否需要立即更新。
• VtableHook::callOriginalFun 函数的使用可能存在潜在的安全风险，需要确保 window->screen()->handle()->cursor() 返回的指针是有效的，并且 QPlatformCursor::changeCursor 函数指针也是正确的。
• xSettings()->registerCallbackForProperty 函数的调用应该检查 xSettings() 是否为空，以避免潜在的空指针解引用。

是否建议立即修改:
是