Retrieves an incident retrospective step

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

{
  "data": {
    "id": "5085d7e8-9156-4a28-8f7a-ede94e2dff73",
    "type": "incident_retrospective_steps",
    "attributes": {
      "retrospective_step_id": "7cb79592-da05-4a8b-943c-485e27a3e17e",
      "incident_id": "d1b69fe6-11ac-46b3-a04b-6ef997a7c01e",
      "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": "2025-08-08T21:52:43.300-07:00",
      "updated_at": "2025-08-08T21:52:43.300-07:00"
    }
  }
}