Change version of `dynaconf` in `requirements.txt`

### Description
With the release of library [dynaconf ](https://github.com/rochacbruno/dynaconf/) version 2.0, the quokka installation broke.

Then we must change the version of `requirements.txt`

```txt
dynaconf>=1.0.0,<=1.2.1
```

### Reference
[Dynaconf 2.0.0](https://github.com/rochacbruno/dynaconf/releases/tag/2.0.0)

