Overview

We have a system that lets you add a tag to a PR you want to be backported to a prior line. In order for that to work, a branch with the name backport/v*.x needs to exist (eg. backport/v3.x). As it is presently, someone has to go and create that branch manually.

Work

The .github/workflows/publish-packages.yml needs to be updated so that, upon publish, it creates a backport branch appropriately named for the major line, if-and-only-if the publish resulted in a major bump.

This will likely be hard and annoying, particularly because of our branch protection rules.