Update RetrospectiveProcessGroup Step

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

{
  "data": {
    "id": "49f445a9-017a-420a-a89f-1f8a553f5732",
    "type": "retrospective_process_group_steps",
    "attributes": {
      "retrospective_process_group_id": "d42816ea-2c28-4eaa-8c62-521f2fe2348a",
      "retrospective_step_id": "afbca943-9d8e-4002-aa1f-83c400b5d3b3",
      "position": 2,
      "updated_at": "2025-10-08T04:38:53.883-07:00",
      "created_at": "2025-10-08T04:38:53.826-07:00"
    }
  }
}