Add pre-built wheels for musllinux?

[N-Wouda]

Is your feature request related to a problem? Please describe.

Right now, Linux wheels are built using manylinux/glibc. But many Docker containers use Alpine because it's much smaller, and that uses musl - not glibc.

If a C toolchain is not found inside the Alpine/musllinux container, the package defaults to a Python implementation, and a RuntimeWarning is issued:

/app/.venv/lib/python3.13/site-packages/google_crc32c/__init__.py:29: RuntimeWarning: As the c extension couldn't be imported, `google-crc32c` is using a pure python implementation that is significantly slower. If possible, please configure a c build environment and compile the extension

This can be corrected if a prebuilt wheel is also made available for musllinux-based systems.

Describe the solution you'd like

Prebuilt wheels for musllinux. I think this can largely follow the manylinux build steps, but I am unsure how this works exactly outside CIBW.

Describe alternatives you've considered

I could set up a C toolchain in a separate builder stage and compile things myself, but that's a lot of additional work that only benefits me - not everyone else also using musllinux.