Test on x86 and apple silicon

[ajfriend]

We've seen a bug (#917) that appears on Apple Silicon but not x86, so adding to the build matrix to test across both.

Also, I shorten the job name so we can see the OS version in the github actions web UI.

Note, I don't think there's a way to guarantee architecture, but it seems like it is usually correlated with macos version:
https://docs.github.com/en/actions/using-github-hosted-runners/using-github-hosted-runners/about-github-hosted-runners#standard-github-hosted-runners-for-public-repositories

[coveralls]

coverage: 98.825%. remained the same
when pulling 2f189c1 on aj/macos_tests
into 9cc20fd on master.

[ajfriend]

If everyone agrees, I can make the same name change on the other tests.

[isaacbrodsky]

I've changed the branch protection rules to not require the previous test names and will update them to require the new ones right after merging

edit: branch protection rules are updated