fix: requirements.txt to reduce vulnerabilities

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-CRYPTOGRAPHY-3172287
- https://snyk.io/vuln/SNYK-PYTHON-CRYPTOGRAPHY-3314966
- https://snyk.io/vuln/SNYK-PYTHON-CRYPTOGRAPHY-3315324
- https://snyk.io/vuln/SNYK-PYTHON-CRYPTOGRAPHY-3315328
- https://snyk.io/vuln/SNYK-PYTHON-CRYPTOGRAPHY-3315331
- https://snyk.io/vuln/SNYK-PYTHON-CRYPTOGRAPHY-3315452
- https://snyk.io/vuln/SNYK-PYTHON-CRYPTOGRAPHY-3315972
- https://snyk.io/vuln/SNYK-PYTHON-CRYPTOGRAPHY-3315975
- https://snyk.io/vuln/SNYK-PYTHON-CRYPTOGRAPHY-3316038
- https://snyk.io/vuln/SNYK-PYTHON-CRYPTOGRAPHY-3316211
- https://snyk.io/vuln/SNYK-PYTHON-WHEEL-3180413