fix: lib/geonames/generators/vendor/guzzlehttp/ringphp/docs/requirements.txt to reduce vulnerabilities (#270)

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-SETUPTOOLS-3180412

Co-authored-by: snyk-bot <snyk-bot@snyk.io>

Author: benjaminpick