Consider uploading musl-cross toolchains for downloads in CI

[loichyan]

GitHub Actions has been blocked due to abuse¹. Although we have cached the download,

1. Caches are not shared across repositories, so each fork requires downloads in the first CI run.
2. GitHub Actions has been blocked since May 27, 2025, and it's unclear when or if they will be unblocked.

Perhaps we should upload the musl-cross toolchains from musl.cc to a GitHub release (either in this repository or a separate one) for downloading in CI.

Footnotes

1. https://github.com/orgs/community/discussions/27906#discussioncomment-3332440 ↩

[timfish]

We're working with the musl.cc maintainers to find a solution but until then, feel free to use my caching proxy musl.cc.timfish.dev. This was built with a simple Cloudflare Worker with origin caching set to 1 week. This ensures it only hits musl.cc for the first request of a file per week.

Once this is resolved I'll actively search Github for my domain and submit PRs before I take down my proxy.