fix: requirements.txt to reduce vulnerabilities

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-CRYPTOGRAPHY-15263096

Author: snyk-bot

requirements.txt

@@ -2,7 +2,7 @@ social-auth-app-django
 social-auth-core>=3.3.0
 kiwitcms-tenants
 certifi>=2023.7.22 # not directly required, pinned by Snyk to avoid a vulnerability
-cryptography>=41.0.4 # not directly required, pinned by Snyk to avoid a vulnerability
+cryptography>=46.0.5 # not directly required, pinned by Snyk to avoid a vulnerability
 pyjwt>=2.4.0 # not directly required, pinned by Snyk to avoid a vulnerability
 requests>=2.32.0 # not directly required, pinned by Snyk to avoid a vulnerability
 sqlparse>=0.5.0 # not directly required, pinned by Snyk to avoid a vulnerability