Add Gitlab CI

Adding the template by itself doesn't run any PHPUnit tests, those need setting up. Also please set the variables to disable all of the failing linting tests and create follow-up issues to do the work to make them pass so they can be re-enabled.

@BenStallings I take it back, the template ran the PHPUnit tests in another module I imported the template for, any idea why it didn't here?

Oh..... this module doesn't have any PHPUnit tests. Right. You would think I knew that.

I've set the test support to be forward-looking rather than supporting old versions. Thank you for making it match the info file in the first instance (I've just changed that too in another issue).

Follow-ups:

📌 Create test Active
📌 CSPell - enable and fix Active
📌 ESLint - enable and fix Active
📌 PHPCS - enable and fix Fixed
📌 PHPStan - enable and fix Active

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