Support `musllinux`

[dhermes]

This is still a WIP, running the following currently segaults:

#!/bin/bash

set -e -x

export CIBW_ARCHS=x86_64
export CIBW_BEFORE_BUILD='python -m pip install cmake nox numpy; nox --session libbezier-release'
export CIBW_BUILD='cp311*musllinux*'
export CIBW_ENVIRONMENT='BEZIER_INSTALL_PREFIX=/project/.nox/.cache/libbezier-release/usr LD_LIBRARY_PATH=/project/.nox/.cache/libbezier-release/usr/lib TARGET_NATIVE_ARCH=OFF'
export CIBW_TEST_COMMAND='pytest {project}/tests/unit'
export CIBW_TEST_REQUIRES=pytest
cibuildwheel --platform linux