[dev]: add homebrew job to publish.yaml

[jsjoeio]

Problem

After we publish a release, we have to manually run a command to update the homebrew code-server package. This should be automated as part of the release process.

Solution

Add a job called homebrew to publish.yaml that waits on npm and then updates code-server on homebrew with bump-formula-pr

Notes

• the script would run brew bump-formula-pr --version=3.9.1 code-server --no-browse
• it may need a GITHUB_TOKEN or something. it would have to open the PR on behalf of someone I think (maybe person who merges PR for release?)
  • probably a security risk here. asher suggested using a bot or something (maybe the cdr bot?)
• the --no-browse flag ensures it doesn't try to open the PR in the browser
• it would have to grab the version from somewhere. maybe we could do a cURL call to the npm API? maybe there's something easier.
• see bump-formula-pr docs here
• look at this PR which added something similar for coder: Add workflow for bumping version homebrew-coder#8