retrieve-tests-metadata fails on fork pipelines
$ retrieve_tests_metadata
/usr/local/bundle/gems/gitlab-4.14.1/lib/gitlab/request.rb:84:in `authorization_header': Please provide a private_token or auth_token for user (Gitlab::Error::MissingCredentials)
from /usr/local/bundle/gems/gitlab-4.14.1/lib/gitlab/request.rb:50:in `block (2 levels) in <class:Request>'
from /usr/local/bundle/gems/gitlab-4.14.1/lib/gitlab/client/pipelines.rb:19:in `pipelines'
from /usr/local/bundle/gems/gitlab-4.14.1/lib/gitlab.rb:28:in `method_missing'
from scripts/api/get_job_id:41:in `find_job_with_filtered_pipelines'
from scripts/api/get_job_id:31:in `execute'
from scripts/api/get_job_id:103:in `<main>'
(https://gitlab.com/winniehell/gitlab/-/jobs/867611135)
This was introduced within the last 3 days and is potentially related to !46424 (merged).