nsd: updating a job with service in nomad provider causes agent error logs

[shoenig]

While debugging #16238 I noticed just updating a job with a service in the nomad provider can trigger agent Error logs, e.g.

2023-03-01T08:57:24.160-0600 [ERROR] nomad.fsm: DeleteServiceRegistrationByID failed: error="service registration not found"
2023-03-01T08:57:24.160-0600 [ERROR] client.rpc: error performing RPC to server: error="rpc error: service registration not found" rpc=ServiceRegistration.DeleteByID server=127.0.0.1:4647
2023-03-01T08:57:24.160-0600 [ERROR] client.rpc: error performing RPC to server which is not safe to automatically retry: error="rpc error: service registration not found" rpc=ServiceRegistration.DeleteByID server=127.0.0.1:4647
2023-03-01T08:57:24.160-0600 [INFO]  client.service_registration.nomad: attempted to delete non-existent service registration: service_id=_nomad-task-ef1dd8fa-b15c-4d9e-3fc4-bede2397bbea-group-group-test-http namespace=default

Unclear if these are benign (the end result is OK - the expected service is in the registry).

To update just change meta.version.

job "bug" {
  group "group" {

    restart {
      interval = "3m"
      attempts = 3
      delay    = "15s"
      mode     = "delay"
    }

    network {
      port "http" { to = 8080 }
    }
    
    meta {
      version = 2
    }

    service {
      name         = "test"
      port         = "http"
      address_mode = "host"
      tags         = []
      provider     = "nomad"
      check {
        type     = "http"
        port     = "http"
        path     = "/"
        interval = "12s"
        timeout  = "6s"

        check_restart {
          limit = 3
          grace = "10s"
        }
      }
    }

    task "task" {
      driver = "docker"
      config {
        image   = "python:3"
        command = "python3"
        args    = ["-m", "http.server", "${NOMAD_PORT_http}"]
        ports   = ["http"]
      }
    }
  }
}