fix: requirements.txt to reduce vulnerabilities

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-TORNADO-17337026

Author: snyk-bot

requirements.txt

@@ -14,5 +14,5 @@ pydantic>=2
 python-dateutil
 requests
 SQLAlchemy>=1.4.1
-tornado>=5.1
+tornado>=6.5.6
 traitlets>=4.3.2