List built-in runtimes

curl --request GET \
  --url https://litellm-rust.onrender.com/api/agent-runtimes \
  --header 'Authorization: Bearer <token>'

{
  "runtimes": [
    {
      "name": "Cursor",
      "default_api_base": "https://api.cursor.com",
      "credential_provider_id": "cursor",
      "credential_provider_name": "Cursor",
      "tools": [
        {}
      ],
      "connected": true,
      "api_base": "<string>",
      "masked_api_key": "<string>"
    }
  ]
}