Release: static binaries for Linux against musl

[darosior]

I found a way to build against a downloaded stdlib in Docker for the MacOS and Windows reproducible builds.

The Guix reproducible build of Linux binaries unfortunately links against a somewhat recent glibc, 2.33: #140 (comment).

I think we should be able to build against musl within the Guix container, and have a x86_64-linux-musl artifact in the release in case users want to run on somewhat old systems (for instance, Debian stable...).

Let's see if i can reasonably achieve that before the release.

[pythcoiner]

not sure if this can be usefull there but i post it in case:

find this here

[darosior]

The latest about this is probably #1080 (comment).