This task will track the #decommission of ganeti VMs registry200[5-8].codfw.wmnet.
The nodes where added via T283321 for tests as part of T264209
[x] - all system services confirmed offline from production use
[x] - set all icinga checks to maint mode/disabled while reclaim/decommmission takes place. (likely done by script)
[x] - remove system from all lvs/pybal active configuration
[x] - any service group puppet/hiera/dsh config removed
[] - remove site.pp, replace with role(spare::system) recommended to ensure services offline but not 100% required as long as the decom script is IMMEDIATELY run below.
[] - login to cumin host and run the decom cookbook: cookbook sre.hosts.decommission <host fqdn> -t <phab task>. This does: bootloader wipe, host power down, netbox update to decommissioning status, puppet node clean, puppet node deactivate, debmonitor removal, and run homer.
[] - remove all remaining puppet references and all host entries in the puppet repo