It was added to avoid symbol conflict between DirectX-header project and Windows SDK, but symbol conflict does not happen Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/6494>
Adding d3d12ipcsink and d3d12ipcsrc elements, equivalent to D3D11 ones. Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/6428>