chore(cmx): Make disk_gib viewable in 'vm ls -o json'

[squizzi]

Quick fix to make disk_gib a viewable entry in vm ls -o json

./bin/replicated vm ls -ojson
[
  {
    "id": "b1f451e6",
    "name": "awesome_easley",
    "distribution": "ubuntu",
    "instance_type": "r1.small",
    "version": "24.04",
    "network_id": "596f0dba10e8a4bfa77e0552eb8aec4aca6ca81d676799eaf0fa4a70889990b2",
    "disk_gib": 20, <---
    "status": "running",
    "created_at": "2025-05-06T20:56:28Z",
    "expires_at": "2025-05-06T21:58:02Z",
    "ttl": "1h",
    "credits_per_hour": 9600,
    "flat_fee": 50000,
    "total_credits": 0,
    "estimated_cost": 59600,
    "direct_ssh_port": 45663,
    "direct_ssh_endpoint": "65.109.157.169",
    "tags": []
  }
]

[dydx]

Nice! Pulling down and running, looks good to me.

➜  replicated git:(squizzi/add-diskgib-to-vm-ls) ./bin/replicated vm ls -o json                                                                                                                                        (⎈|eks-staging.tail1ed40.ts.net:default)
[
  {
    "id": "655f7afa",
    "name": "testing",
    "distribution": "ubuntu",
    "instance_type": "r1.small",
    "version": "24.04",
    "network_id": "148e3a53e3c3e7e8bfea183eeb7028d08e91e9820fcb6fce90e7e7b8d90b0ca3",
    "disk_gib": 50,
    "status": "provisioning",
    "created_at": "2025-05-06T21:30:25Z",
    "expires_at": "0001-01-01T00:00:00Z",
    "ttl": "1h",
    "credits_per_hour": 9600,
    "flat_fee": 50000,
    "total_credits": 0,
    "estimated_cost": 59600,
    "tags": []
  }
]