Retire DGU Publish

[AgaDufrat]

Why

The app is no longer used.

What/How

Follow the steps in: https://docs.publishing.service.gov.uk/manual/retiring-an-application.html

• Remove end-to-end tests
  Remove any end-to-end tests specific to the application.

• Update Release app
  Mark the application as archived in the Release app.

• Update DNS
  Request any public DNS entries be removed. If the app had an admin UI, it will have had public DNS entries in the publishing.service.gov.uk domain. Follow the instructions for DNS changes in order to remove these.

• Remove from the GOV.UK architecture diagram

• Drop database
  Drop the database, if present - note that this might be in RDS, but it might also exist as a MongoDB or DocumentDB database.

• Remove from Sentry

• Remove from helm-charts

• Update the README
  Add a note to the top of the README explaining that the repo has been retired and, if applicable, what has replaced it.

• Close all issues and pull requests
  This is necessary because GitHub does not automatically close or archive PRs/issues when archiving a repo. For example, if an old PR is still open when the repo is archived, its author will be unable to close it and it will forever remain on their github.com/pulls page. If there are more than a handful of open issues/PRs, consider using the GitHub CLI tool (gh pr, gh issue).

• Unpublish the GitHub pages site (if it has one)
  Archiving a repo does not remove its GitHub Pages site (if any). The site stays up but the settings become read-only. ⚠️ Take care when unpublishing a GitHub Pages site which has a custom domain. If you leave a dangling DNS record pointing at GitHub, it will likely be hijacked by spammers (or worse). Check whether the site has any custom domains configured. This is under Settings, Pages, Custom domain in the GitHub web UI. Do not remove the custom domain.
  Remove any DNS records that point to the site, if the site uses a custom domain. Unpublish the GitHub Pages site.

• Archive the repo
  Go into the repository settings in GitHub, and archive the repo.

• Update the Developer Docs
  If the repo is listed in govuk-developer-docs, mark the application as retired. If the repo wasn’t already listed in Developer Docs then don’t add it.

• Remove datagovuk_publish from GitHub config #1592

• Remove references