Move CI + testing into the main course

[anenadic]

At the November 2025 workshop for AstraZeneca we delivered the CI extra episode after the episode on testing to a great success. It makes sense to spend time on this and we managed to deliver the whole course (having toned down a bit on publishing and archiving code and DOIs on Zenodo).

[tobyhodges]

The CI episode looks really nice and it would be valuable if included as a proper episode, provided we can afford time in the schedule. I would like to wait to hear from some of the beta pilots, to gather feedback on whether or not there is space for another episode without overloading the workshop.