Cleanup workflows and artifacts on expiration

Depends https://gitlab.com/arkindex/ponos/-/issues/116

When a workflow becomes expired, we can safely delete:

• all its tasks in DB
• all its tasks logs on bucket
• all its tasks artifacts in DB
• all its tasks artifacts on bucket
• the workflow
• 🗨 We need to discuss if the deletion of DataImport is needed (we could retry old dataimports...)

⚠ There are two cases where the deletion is skipped:

1. if any task artifact in the workflow is used as a worker version docker image with GitRef branch=master
2. if any task artifact in the workflow is used as a worker version docker image with GitRef on any tags

Basically we can remove all docker images on outdated branches, but need to keep current master and tags