Update an override shift

curl --request PUT \
  --url https://api.rootly.com/v1/override_shifts/{id} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/vnd.api+json' \
  --data '{
  "data": {
    "type": "shifts",
    "attributes": {
      "user_id": 123
    }
  }
}'

{
  "data": {
    "id": "6bf07d05-3426-4863-b7a9-12247fbd958c",
    "type": "shifts",
    "attributes": {
      "schedule_id": "c2949531-b89e-4a7a-851e-da2cfc2de747",
      "rotation_id": "01cf3ff5-1eb5-489a-8339-08f55d910b79",
      "starts_at": "2025-08-01T15:50:37.000-07:00",
      "ends_at": "2025-08-01T23:50:37.000-07:00",
      "is_override": true
    },
    "relationships": {
      "shift_override": {
        "data": {
          "id": "cf2e3be9-1f8b-4914-9d42-22a369c2e375",
          "type": "shift_overrides"
        }
      },
      "user": {
        "data": {
          "id": "356",
          "type": "users"
        }
      }
    }
  }
}