Retrieves an incident retrospective step

curl --request GET \
  --url https://api.rootly.com/v1/incident_retrospective_steps/{id} \
  --header 'Authorization: Bearer <token>'

{
  "data": {
    "id": "264e00e8-5851-42a8-af5c-bdb55088f6bb",
    "type": "incident_retrospective_steps",
    "attributes": {
      "retrospective_step_id": "892e5b64-d8c5-4b58-acfe-439d44aca49e",
      "incident_id": "a4605dc3-d7a1-4e71-97d1-706d79426041",
      "title": "Step 4",
      "description": null,
      "due_date": null,
      "user_id": null,
      "kind": "custom",
      "position": 1,
      "skippable": false,
      "status": "todo",
      "status_changed_at": null,
      "status_changed_by_id": null,
      "created_at": "2025-10-13T12:48:14.592-07:00",
      "updated_at": "2025-10-13T12:48:14.592-07:00"
    }
  }
}