Add Gitlab CI template file (D7)

Update: I found the reason.

"test_dependencies" modules are not downloaded, so it fails silently. See the job with extra output here: https://git.drupalcode.org/issue/metatag-3420192/-/jobs/867502

GitLab CI no longer brings automatically the test dependencies. For Drupal 10, you need to add them to the "require-dev" section in the "composer.json" file. But we have no mechanism for now to do the same for Drupal 7.

I will work on that issue to make it happen.

The tests are now running: https://git.drupalcode.org/issue/metatag-3420192/-/jobs/868201
See the results here: https://git.drupalcode.org/issue/metatag-3420192/-/pipelines/100353/test...
Some of them are successful, some of them fail, but those can be worked on in a follow-up.

We added a new variable to the templates, which can be seen here: https://git.drupalcode.org/project/metatag/-/merge_requests/100/diffs#58...

Note that the issue #3422720: [D7] Test dependencies are not automatically brought → is still not merged. It'd be great if you can RTBC it if you are happy with the solution, then we can make the final clean up here (as it is still pointing to the fork instead of the main templates).

The changes in the related issue were merged into the "gitlab_templates".

That means that the tests should start running here just by running the pipeline again:
- Yesterday: https://git.drupalcode.org/project/metatag/-/jobs/872527 (no tests run)
- Today: https://git.drupalcode.org/issue/metatag-3420192/-/jobs/878468 (tests are running)

Assuming that the test errors would be tackled in separate issue(s), I am marking this one as RTBC.

Done with the quick test. Still RTBC.

The tests still fail, so let's fix this.

I'm going to re-test the second MR (137) from #3422720: [D7] Test dependencies are not automatically brought → , now that ✨ Preserve original composer.json in the modules directory Fixed is complete. Will revert when done.

I have done the testing, all successful, and put the values back to the standard

  - project: $_GITLAB_TEMPLATES_REPO
    ref: $_GITLAB_TEMPLATES_REF

The phpunit tests fail in the same way as before, with extra html being piped to the log.

Before digging much further into individual errors, it'd be great to compare with the current DrupalCI: https://www.drupal.org/node/640498/qa →

GitLab CI is running on PHP8.1 by default, so maybe we can change the PHP version of this MR to use the last known passing tests version (PHP7.4).

Yeah, some of the dependencies fail with PHP 8.0 due to needing patches.

I think we might need to try loading the devel module from D7Security via a composer.json file.