Log Message:
Update blender to 4.2.1

(Not sure why I no longer need patch-source_blender_gpu_intern_gpu_matrix.cc)

The next generation of the render engine EEVEE is here. Completely
rewritten from scratch to allow global illumination, displacement,
better SSS, viewport motion blur, and so much more.
-> https://developer.blender.org/docs/release_notes/4.2/eevee_migration/

Many many changes, see https://developer.blender.org/docs/release_notes/4.2/
for details.