Configure GitLab CI matrix testing

Alas, https://git.drupalcode.org/project/entitygroupfield/-/pipelines/12586 failed. Opened some MR threads for parts that seem broken.

dww → credited cmlara → .

dww → credited moshe weitzman → .

Got some solid help in Slack from @cmlara and @moshe, thanks!

My confusion is that when you have a job inheriting from something else, you have to go out of your way to merge steps using
!reference[job-id, thing].

https://git.drupalcode.org/project/entitygroupfield/-/pipelines/12666 is now working as expected, and the same commit ran to completion with the right versions of everything when I ran it locally. Now we just have to see that it works on d.o, too. 😅

Excellent, only once the canary config passed build, validate and test did any of the matrix build jobs launch:

Huzzah, https://git.drupalcode.org/project/entitygroupfield/-/pipelines/12666 passed on all 4 configurations. 🎉

Merged to 2.0.x and pushed.

There are probably cleaner ways to implement this, but it's a start. 😅 Let's call this fixed, and open follow-ups for future improvements.

Thanks again!
-Derek

dww → closed merge request !10

Automatically closed - issue fixed for 2 weeks with no activity.