fix: requirements.txt to reduce vulnerabilities

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-REQUESTS-10305723

Author: snyk-bot

requirements.txt

@@ -1,4 +1,5 @@
 hammock==0.2.4
 pytest==8.2.1
 pytest-asyncio==0.23.7
-python-dotenv==1.0.1
+python-dotenv==1.0.1
+requests>=2.32.4 # not directly required, pinned by Snyk to avoid a vulnerability