fix: requirements.txt to reduce vulnerabilities

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-URLLIB3-14896210

Author: snyk-bot

requirements.txt

@@ -33,6 +33,6 @@ SQLAlchemy==2.0.22
 tomli==2.0.1
 tomlkit==0.12.1
 typing_extensions==4.8.0
-urllib3==2.0.7
+urllib3==2.6.3
 Werkzeug==3.0.1
 WTForms==2.3.3