fix: requirements.txt to reduce vulnerabilities

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-WERKZEUG-6808933

Author: snyk-bot

requirements.txt

@@ -1,2 +1,3 @@
 Flask>=2.2.0
-sentry-sdk[flask]==2.19.2
+sentry-sdk[flask]==2.19.2
+werkzeug>=3.0.3 # not directly required, pinned by Snyk to avoid a vulnerability