packages.debian.org hasn't been updated for non-free-firmware
It looks trivial to provide a blind MR without any testing ...
But this really needs testing :-/,
someone willing to clone the whole setup.
https://packages.debian.org/source/unstable/amd64-microcode : 404
https://packages.debian.org/source/unstable/intel-microcode : 404
No commit for one year