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": "82272060-4722-4bba-947a-d3a7f3adbd64",
    "type": "retrospective_process_group_steps",
    "attributes": {
      "retrospective_process_group_id": "dd7d715f-a9c1-435c-ab55-ba3c3a139850",
      "retrospective_step_id": "95e41b1b-e4a8-4b57-b2fb-89deb16a3d56",
      "position": 2,
      "updated_at": "2025-11-06T13:28:53.108-08:00",
      "created_at": "2025-11-06T13:28:53.037-08:00"
    }
  }
}