Issue #3379349 Add GitLab CI config file.
Closes #3379349
Add the standard gitlab ci template from https://git.drupalcode.org/project/gitlab_templates/-/blob/1.0.x/gitlab-ci/template.gitlab-ci.yml
Following this guide https://www.drupal.org/docs/develop/git/using-gitlab-to-contribute-to-drupal/gitlab-ci