CI-in-OCaml: [*release_tag(test)] pipelines

Context

Builds on !11461 (merged)

Stack

1. !11999 (merged) (add ci/lib_gitlab_ci). Look here for rationale.
2. !12000 (merged) (add ci/bin)
3. !10948 (merged) (translate .gitlab-ci.yml)
4. !11461 (merged) (translate latest_release pipeline)
5. !11500 (merged) (translate *release_tag(test) pipelines) <- You are here
6. !11501 (merged) (translate master_branch pipeline)
7. !11534 (closed) (translate schedule_extended_test pipeline)
8. !11671 (closed) (translate before_merging pipeline)

Manually testing the MR

Checklist

• Document the interface of any function added or modified (see the coding guidelines)
• Document any change to the user interface, including configuration parameters (see node configuration)
• Provide automatic testing (see the testing guide).
• For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, CHANGES.rst at the root of the repository for everything else).
• Select suitable reviewers using the Reviewers field below.
• Select as Assignee the next person who should take action on that MR