fix: requirements.txt to reduce vulnerabilities

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

Author: snyk-bot

requirements.txt

@@ -4,3 +4,4 @@ PyJWT>=2.0.0, <3.0.0
 aiohttp>=3.9.4
 aiohttp-retry>=2.8.3
 certifi>=2023.7.22 # not directly required, pinned by Snyk to avoid a vulnerability
+urllib3>=2.2.2 # not directly required, pinned by Snyk to avoid a vulnerability