Automate picking the OS versions

[aptinio]

[aptinio]

@ericmj, this new implementation is much slower. In my testing, the builds/0 private function takes about 5 to 15 seconds. The previous implementation is in the order of a hundredth to a tenth of a second. I tried fetching only 100 tags per repo and it's still in the order of a second.

For me, the major disadvantage of the previous implmentation is that

It's still a firm Work In Progress

as stated in their README, but they wrote that 7 years ago :relaxed:

Please let me know if you want me to force-push the previous implementation.

[ericmj]

I don't think performance is a big concern here. This check runs every 15min and has plenty other slow parts.

Maybe we could parallelize the check for each OS using Task.async_stream?

[aptinio]

@ericmj, rebased and used Task.async_stream.

[ericmj]

Thank you @aptinio!