Support Alpine Linux

Nobody has claimed this yet.

Mason currently supports most linux systems (like ubuntu, debian, amazon linux, rhel, centos, fedora) and the binaries mason produces run across all those systems. This is possible because:

- the C and C++ standard libraries on these systems support symbol versioning
- all these linux distros default to the same C and C++ standard libraries
- We statically link all other deps into the binaries

Alpine Linux is a different story since alpine uses musl for the C standard library rather than glibc. So to support Alpine linux we'll need to:

- have a new linux variant that is `linux-musl`
- we'll need to detect this platform automatically
- we'll need to create a dockerfile using alpine to do the binary builds for publishing
- we'll need to add this custom dockerfile to CI
- we'll need to build binaries for lots of mason packages

This is a large lift, but one that may be worthwhile because:

- musl is a great, small, well supported C standard library
- alpine linux is popular among docker users since small images are made with it

Start by reviewing Mason's existing Linux variant and platform-detection paths, then inspect the current binary build and publishing CI setup. Compare those workflows with Alpine's musl environment and define the Alpine Docker build path. Done means linux-musl is detected, Alpine binaries are built and published, and CI covers the new variant across the required Mason packages.

Written by the indexing model from the issue text.