fix: docs/requirements.txt to reduce vulnerabilities (#232)

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-JINJA2-9292516

Co-authored-by: snyk-bot <[email protected]>

Author: replit-reliability

docs/requirements.txt

@@ -60,7 +60,7 @@ iso8601==2.1.0
     # via pyseto
 itsdangerous==2.2.0
     # via flask
-jinja2==3.1.5
+jinja2==3.1.6
     # via
     #   flask
     #   sphinx