Build wheel for musllinux (musl libc)

[sanmai-NL]

Checklist

• [x] This is a new feature, not a refactoring suggestion
• [x] I have checked for this feature in the Sourcery documentation
• [x] I have checked there are no open requests referencing the same feature

Description

To use Sourcery as part of CI, support for Alpine Linux is helpful, since this Linux distro is used a lot in container space. A musllinux wheel is lacking, however.