Failed on valid schema

https://wikimedia.org/api/rest_v1/?spec

```
.pnpm/openapi@1.0.1/node_modules/openapi/src/lib/get-ref.js:4
  return refArr.reduce((memo, key) => memo[key], object);
                                          ^

TypeError: Cannot read properties of undefined (reading 'editors-by-country')
```