[ignore] Rules tests in GitLab CI

OK. I was going to say that we probably need to add a couple of the other phpunit variants. Then I looked at the .gitlab-ci.yml and they are already there https://git.drupalcode.org/project/config_inspector/-/blob/2.1.x/.gitlab...
But as these others are not showing in the pipeline is does imply that the 'when:on success' does need to be repeated in each of the rules for the other variants.

Let's add it just for one of them, and see if just that one extra job appears.

I also note that this project does not modify any phpunit job, whereas my Scheduler test did. But I still did not have 'when:on success' in any of the scheduler customised phpunit jobs. The docs do say it is the default but on reading carefully the paragraphs

The job is added to the pipeline:

If an if, changes, or exists rule matches and also has when: on_success (default), when: delayed, or when: always.
If a rule is reached that is only when: on_success, when: delayed, or when: always.

The job is not added to the pipeline:

If no rules match.
If a rule matches and has when: never.

I think the reason we got no job is that we only had rules that did not match. So the 'default' is only a default for a rule that matches.
OK, we can fix this :-) but the rules still need to be simple to extend, and allow customisations.