Fix version of Modin for building latest documentation

### Describe the problem


Latest [documentation ](https://modin.readthedocs.io/en/latest/index.html) for Modin is built using [latest public](https://github.com/modin-project/modin/blob/master/docs/requirements-doc.txt#L14) Modin release. Need to align versions of docs and sources in doc building process.