Build for armv7 and arm64 with musl

[derphilipp]

Which operating systems are supported by this tool?

• Building for armv7 / arm64 with muscl, enables use of topgrade on distributions like alpine on multiple different devices, like the raspberry pi. As even distributions like 'home assistant' build upon those distributions, it would be awesome to have it available as a download

[smcavoy]

Hello, Topgrade is available in the Alpine Linux testing repo.

I can see about getting it moved in to community before the next release which is in about 6 months.