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": "6b1bdce2-add1-4b8f-b3ce-34c374a0379f",
    "type": "retrospective_process_group_steps",
    "attributes": {
      "retrospective_process_group_id": "68745f51-f5c5-4d46-b324-0fc1f595956b",
      "retrospective_step_id": "5d6f6005-4860-4e0b-a8ee-4ec66cf05c84",
      "position": 2,
      "updated_at": "2025-08-15T07:15:19.661-07:00",
      "created_at": "2025-08-15T07:15:19.601-07:00"
    }
  }
}