Bundle prometheus and sentry into the Docker image

[benbz]

Pull Request Checklist

• Pull request includes a changelog file. The entry should:
  • Be a short description of your change which makes sense to users. "Fix a bug that prevented receiving messages from other servers." instead of "Move X method from EventStore to EventWorkerStore.".
  • Include 'Contributed by Your Name.' or 'Contributed by @your-github-username.' — unless you would prefer not to be credited in the changelog.
  • Use markdown where necessary, mostly for code blocks.
  • End with either a period (.) or an exclamation mark (!).
  • Start with a capital letter.
• Pull request includes a sign off

Re-does #325 post-poetry.

As of poetry 1.2.0b2 / python-poetry/poetry#5452 this can be done with --all-extras instead

[DMRobertson]

Sorry, I must have missed this in the poetry work.

I sanity checked that the docker file builds and that it contains prometheus and sentry in the venv. LGTM!