WinRT build fails to compile due to missing filesystemwatcher in qfilesystemwatcher.h

When trying to compile a UWP project using CMake and Qt 5.15.0 (not 5.15.5 because that fails to compile, so I downloaded some precompiled binaries from here), compilation fails due to this error:

static_assert failed: 'Required feature filesystemwatcher for file ---Qt\Qt5.15.0\winrt_x64_msvc2019\include\QtCore\qfilesystemwatcher.h not available.'

I'm not sure what is going on here, given that this version of Qt was compiled for UWP.

I've attached the logs from an old failed Qt 5.15.5 build, showing why I couldn't compile it.