Complete GitLab-CI migration

Hi, I’m working on this issue as part of Drupal Global Contribution Weekend 2023.

Any help with Gitlab welcome, see comments above.

See also 📌 Implement Gitlab CI Active , which restarts this from a clean slate.

Updating the title.

Repurposing for the followup work after the initial Gitlab CI conversion completed at 📌 Implement Gitlab CI Active .

Actually, there's not much work remaining for now, so marking fixed. I moved the credit to the other issue.

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