py-requests: updated to 2.23.0

2.23.0:
**Improvements**
- Remove defunct reference to `prefetch` in Session `__attrs__`

**Bugfixes**
- Requests no longer outputs password in basic auth usage warning.

**Dependencies**
- Pinning for `chardet` and `idna` now uses major version instead of minor.
  This hopefully reduces the need for releases everytime a dependency is updated.

(adam)