Rake task to expire artifacts which do not have an expiration

What does this MR do and why?

Due to unknown reasons some build artifacts on GitLab.com are missing an expiration date.

This MR introduces a rake task which will be used to cleanly expire these artifacts.

Related:

• https://gitlab.com/gitlab-com/ops-sub-department/section-ops-request-for-help/-/issues/271(internal)
• Zendesk #484239(internal)