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": "d4e288a7-62df-443c-8f78-2193d43525a1",
    "type": "retrospective_process_group_steps",
    "attributes": {
      "retrospective_process_group_id": "02d05adf-e1b9-4ea5-925b-322ba1ae8f2b",
      "retrospective_step_id": "853a077c-7a55-4ca1-b12d-82a2584a7093",
      "position": 2,
      "updated_at": "2025-09-05T00:39:54.416-07:00",
      "created_at": "2025-09-05T00:39:54.351-07:00"
    }
  }
}