List machine versions

[
  {
    "config": {
      "auto_destroy": true,
      "guest": {
        "cpu_kind": "<string>",
        "cpus": 2,
        "memory_mb": 2
      },
      "stop_config": {
        "signal": "<string>",
        "timeout": 123
      },
      "workload": {
        "env": [
          "<string>"
        ],
        "image": "<string>",
        "init": {
          "cmd": [
            "<string>"
          ],
          "entrypoint": [
            "<string>"
          ],
          "user": "<string>"
        },
        "restart_policy": {
          "max_retries": 123,
          "policy": "<string>"
        },
        "type": "<string>"
      }
    },
    "id": "<string>",
    "machine_id": "<string>"
  }
]