bug#73295: TeX font maps are not reproducible

[Konrad Hinsen]

Hi everyone,

The font maps generated during profile creation (procedure
texlive-font-maps in guix/profiles.scm) are not reproducible: the order
in which the files are listed in the ls-R file is not deterministic.

As a consequence, files generated from profiles, such as Docker or
Singularity containers, are not reproducible.

I suspect that the culprit is the mktexlsr utility which generates the
non-deterministic ls-R files. It's worth exploring if it can be patched.

Cheers,
  Konrad.