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": "9b7d2033-a830-4519-a136-51846a62a02a",
    "type": "retrospective_process_group_steps",
    "attributes": {
      "retrospective_process_group_id": "0c112885-d871-489d-8ee0-c16103ecdd81",
      "retrospective_step_id": "5c3d7b10-c140-4126-b714-26276eee7971",
      "position": 2,
      "updated_at": "2025-10-28T10:26:46.164-07:00",
      "created_at": "2025-10-28T10:26:46.086-07:00"
    }
  }
}