Retire chifflet and chetemi clusters

Related to this jenkins test.

Chetemi and chifflet clusters have been set retired. But they were not removed from the ref-repo, and the puppet/hiera configuration files were not removed.

This merge request fix this.

assigned to @pijacquo

added 3 commits

• c677feb4 - 1 commit from branch master
• 276c10a8 - [lille][chetemi] Retire cluster chetemi.
• 63ed2a68 - [lille][chifflet] Retire cluster chifflet.

Compare with previous version

enabled an automatic merge when the pipeline for 63ed2a68 succeeds

merged

mentioned in commit d49ced42