add psql backups to the retirement procedure

howto/retire-a-host.md

@@ -251,6 +251,11 @@ of an emergency:
      
      TODO: add to fabric
 
+ 13. after 30 days delay, remove PostgreSQL backups on the storage
+     server (currently `/srv/backups/pg` on `bungi`), if relevant
+
+     TODO: add to fabric
+
 Equivalent retirement checklist to copy-paste in retirement tickets:
 
  1. [ ] announcement
@@ -265,3 +270,4 @@ Equivalent retirement checklist to copy-paste in retirement tickets:
  10. [ ] remove from racks
  11. [ ] remove from reverse DNS
  12. [ ] remove from bacula director
+ 13. [ ] remove PostgreSQL backups