fix: example/requirements.txt to reduce vulnerabilities

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-REQUESTS-6928867
- https://snyk.io/vuln/SNYK-PYTHON-URLLIB3-7267250

Author: snyk-bot

example/requirements.txt

@@ -4,4 +4,5 @@ gunicorn
 oic>=1.2.1
 setuptools>=65.5.1 # not directly required, pinned by Snyk to avoid a vulnerability
 werkzeug>=3.0.1 # not directly required, pinned by Snyk to avoid a vulnerability
-requests>=2.32.0 # not directly required, pinned by Snyk to avoid a vulnerability
+requests>=2.32.2 # not directly required, pinned by Snyk to avoid a vulnerability
+urllib3>=2.2.2 # not directly required, pinned by Snyk to avoid a vulnerability