Check for running jobs on the GitLab omnibus installation not requiring authentication

before a GitLab upgrade, I am rejecting jobs with this content in the /etc/gitlab/gitlab.rb file:

nginx["custom_gitlab_server_config"] = "location = /api/v4/jobs/request {\n    deny all;\n    return 503;\n  }\n" # MAINTENANCE INC

Now I want to wait for all jobs to be finished on the instance possibly not using the API, because I don’t wish to deal with authentication, if I have root access already.
I should be able to check via the gitlab-rails console, no? Or is there a better approach?
How would that look like?