Consul Enterprise agents all belong to an admin partition. Fingerprint this
attribute when available. When a Consul agent is not explicitly configured with
"default" it is in the default partition but will not report this in its
`/v1/agent/self` endpoint. Fallback to "default" when missing only for Consul
Enterprise.
This feature provides users the ability to add constraints for jobs to land on
Nomad nodes that have a Consul in that partition. Or it can allow cluster
administrators to pair Consul partitions 1:1 with Nomad node pools. We'll also
have the option to implement a future `partition` field in the jobspec's
`consul` block to create an implicit constraint.
Ref: https://github.com/hashicorp/nomad/issues/13139#issuecomment-1856479581