ci: Enforce Conventional Commit PR titles

[DiamondJoseph]

See also: the proposed ADR in this PR

And how release-please was able to automate a release in this example repository.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.42%. Comparing base (20e0377) to head (09d71f5).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #918   +/-   ##
=======================================
  Coverage   94.42%   94.42%           
=======================================
  Files          40       40           
  Lines        2403     2403           
=======================================
  Hits         2269     2269           
  Misses        134      134           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[callumforrester]

If DiamondLightSource/python-copier-template#255 is merged upstream then we can just update the copier template rather than merge this, correct?

[DiamondJoseph]

No, the change to the python-copier-template only enables it for the copier template.

Why do you not want to enforce squash-and-merge? It's already the default option for PRs in this repository and looking at the first page of the git history, it's always been used.

[callumforrester]

Happy to enforce it for blueapi, not for copier template projects, so all good. Should have a separate ADR here though.

[callumforrester]

LGTM, I recommend drawing attention to this one in slack on merge, in the core team channel at least and possibly wider