Cleanup orphan artifacts

Closes #970 (closed)

requested review from @babadie

assigned to @erwanrouchet

added 4 commits

• e03762e0...d2efb08c - 2 commits from branch master
• 773ce954 - Add cleanup for orphaned Ponos artifacts
• 87f79eb8 - Fix tests

Compare with previous version

enabled an automatic merge when the pipeline for 87f79eb8 succeeds

mentioned in commit 9090e2ed

merged