Hi,
I've now finalized my patch to bring up MuseScore to version 4.4. As
different downstream packagers have experienced this upgrade was trickier
than usual. Fortunately I could draw from their experiences to reach my now
working version. Loading, arranging and playback of arrangements works
well. Though there is graphical lag during playback with the playhead
visibly juttering.

On the Guix side I had to change the build system for Harfbuzz in order for
it to build correct CMake-files for MuseScore to consume - rather than
build its vendored version. The problem of course is that harfbuzz has
about 15 000 dependants. So I created a temporary package named
harfbuzz-meson to later be removed with a core-updates merge.

So the patches 0001 and 0002 are for master and 0003 is for core-updates.