Add support for new Gitlab CI Pipelines

I added the CI configuration templates from DF. I also fixed most of the phpcs and phpstan most evident erros, but did not fix them all, because some of them might require some discussion in a different issue.

I believe this should be merged to the development branch, and then fix the remaining validation errors with different issues, so i am setting the issue to "needs review".

Changing issue priority to major per https://www.drupal.org/docs/develop/managing-a-drupalorg-theme-module-or... →

Thanks for working on this. Not sure if it is a good idea to do such a big refactoring directly with adding a GitlabCI.

5.0.x tests are green in DrupalCI ( https://www.drupal.org/pift-ci-job/2733012 → ), so I suppose these should be green in GitlabCI as well. We just need to turn off the linting, PHPCS and so on (see the SKIP_XX variables here: https://project.pages.drupalcode.org/gitlab_templates/jobs/) for the beginning. Then we can probably fix these issues in the separate issue. Otherwise this will be very hard to review. Or the second option is to create two MRs here - one with just GitlabCI addition (together with skipping additional linting) - which could be committed pretty fast and second with all other changes (which could take some time to review / finish). But not sure about the preference of the 8.x branch maintainers (I maintain only 7.x branch). Thanks!

IMO we could merge the issue with the fixes i already made, and then fix the remaining ones in different issues.
The eslint and phpstan validations are set as "allowed to fail", si i think it is ok to leave them on, but it is also ok to turn them off, and then turn them off in the specific issues we create as a follow up.

Hopefully the mantainers will give some feedback on the issue.

To echo #6, ideally this MR would be just to enable gitlab and not all the code standard changes.

Thank you for the feedback @heddn and @poker10

I have reverted the commits that added corrections for the style issues in the gitlab-ci pipeline, so those can be addressed in separate issues.
I did not disable the failing steps in the pipeline since there are marked as "allowed to fail", but if you believe they should be disabled until they are fixed in the separate issue, let me know.

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