gitlab-ci job "build-docs" is failing

build-docs [1] is failing in before script stage [2].
My best guess is that this is due to unpublished artifacts of the previous (build) step [3].

The gitlab-ci is in this state since some time. I could not find the date when the issue first happened.

[1] For example: Job #23725376 failed for 96af9ffe:
[2] https://gitlab.cern.ch/lhcb/Moore/-/blob/master/.gitlab-ci.yml#L88
[3] https://gitlab.cern.ch/lhcb/Moore/-/jobs/23720319#L239