windows: fix support for WIN_SDK < 19041

inspired by : https://gitlab.kitware.com/cmake/cmake/-/blob/v3.17.3/Modules/InstallRequiredSystemLibraries.cmake#L339-358
Since CMake doesn't really has a way of providing the Win10 SDK's version ( see: https://gitlab.kitware.com/cmake/cmake/-/issues/20773 )
we read the XML file set up by the SDK and filter the SDK version out of it
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passed linux kf5-qt5 qt5.15 #112145

00:04:06

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