feat(rel): add steps to update main with latest versions

[jdpleiness]

Add a step to our build process that creates a PR with the latest release version to merge back into main.

Also updates broken Github action Python dependency in CI.

Checklist

• [NA] Follow the manual testing process
• [NA] Update changelog
• [NA] Update Kubernetes update doc

Test plan

Part of CI steps during release process.

[Chickensoupwithrice]

Thank you 🙏🏽
This had been bothering me

[Chickensoupwithrice]

I'm not following something here. We pull main, switch to main, and then switch to another release-branch, and then perform the changes we'd already performed on the previous release branch, in the promote to public step.

What's the expected flow here? We close the other (internal) branch PR that gets generated and merge this one?

[DaedalusG]

The earlier step is just assigning the name right? The git switch main part is also confusing to me though. In all these deploy repos we're now cutting releases from a release branch, so this likely needs to be whatever the base branch sg release <>

Otherwise this just looks like making sure things are up to date with main 🤔

[jdpleiness]

So the idea here is to update main with the latest version of Sourcegraph. So to do that we:

• checkout main
• create a new PR off main with the updated version and tags we need via these steps:
  • create a new branch
  • make the changes
  • commit the changes
  • open the PR

We don't really need to do anything with the other release PRs. They are similar, but not really related. The idea here is to keep them separated and intentionally create a PR for the changes we want made to main.

This will create a new PR that we just then have to merge.

Unless I'm missing something here 😆

We close the other (internal) branch PR that gets generated and merge this one?

Yup, really those should be auto-closed in the future in my opinion, as they are really just placeholders for steps in our release process.