Evaluate whether to use upstream's new release-* workflows

[abathur]

In the process of porting more of their CI from buildkite to GHA, cole added 3 new workflows:

.github/workflows/release-branches.yml
.github/workflows/release-prs.yml
.github/workflows/release-tags.yml

We have these disabled here for now. Domen separately added .github/workflows/release-script.yml.

This probably isn't actionable until/around the point where we're getting infra set up here. Hopefully "infra" will be S3, and we can use the same workflows upstream does with different buckets, URLs, and credentials.