Creates an incident role

curl --request POST \
  --url https://api.rootly.com/v1/incident_roles \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/vnd.api+json' \
  --data '
{
  "data": {
    "type": "incident_roles",
    "attributes": {
      "name": "<string>",
      "summary": "<string>",
      "description": "<string>",
      "position": 123,
      "optional": true,
      "enabled": true,
      "allow_multi_user_assignment": true
    }
  }
}
'

{
  "data": {
    "id": "991f8748-b6c1-4955-a112-8963105ca6ca",
    "type": "incident_roles",
    "attributes": {
      "slug": "my-incident-role",
      "name": "My Incident Role",
      "summary": "My Incident Role summary",
      "description": "My Incident Role description",
      "position": 1,
      "optional": false,
      "enabled": true,
      "allow_multi_user_assignment": true,
      "created_at": "2025-12-24T09:26:32.390-08:00",
      "updated_at": "2025-12-24T09:26:32.390-08:00"
    }
  }
}