add linux-armv7l-musl and linux-armv6l-musl prebuilts

[chrisns]

implements https://github.com/serialport/bindings-cpp/issues/139#issuecomment-1822452616 suggestion from @alexojegu 🤞 hopefully this can fix some of the issues we've got with bundling zwave-js cc @robertsLando https://github.com/zwave-js/zwave-js-ui/pull/3440

[robertsLando]

CC @GazHank 🙏🏻

[alexojegu]

@chrisns, I also made a PR at https://github.com/prebuild/docker-images/pull/31 to implement it directly to prebuildify, at least for armv7l.

[chrisns]

Oh, cool. A race! 😂

[hardillb]

Any movement on getting this or @alexojegu's PR merged please

[alexojegu]

@chrisns I think I'm winning https://github.com/prebuild/prebuildify-cross/issues/17 just one last sprint https://github.com/serialport/bindings-cpp/pull/166 😂