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-CRYPTOGRAPHY-5663682
- https://snyk.io/vuln/SNYK-PYTHON-CRYPTOGRAPHY-5777683
- https://snyk.io/vuln/SNYK-PYTHON-CRYPTOGRAPHY-5813745
- https://snyk.io/vuln/SNYK-PYTHON-CRYPTOGRAPHY-5813746
- https://snyk.io/vuln/SNYK-PYTHON-CRYPTOGRAPHY-5813750
- https://snyk.io/vuln/SNYK-PYTHON-CRYPTOGRAPHY-5914629
- https://snyk.io/vuln/SNYK-PYTHON-CRYPTOGRAPHY-6036192
- https://snyk.io/vuln/SNYK-PYTHON-CRYPTOGRAPHY-6050294
- https://snyk.io/vuln/SNYK-PYTHON-CRYPTOGRAPHY-6092044
- https://snyk.io/vuln/SNYK-PYTHON-CRYPTOGRAPHY-6126975
- https://snyk.io/vuln/SNYK-PYTHON-CRYPTOGRAPHY-6210214
- https://snyk.io/vuln/SNYK-PYTHON-CRYPTOGRAPHY-6913422
- https://snyk.io/vuln/SNYK-PYTHON-FLASK-5490129
- https://snyk.io/vuln/SNYK-PYTHON-GEVENT-5906371
- https://snyk.io/vuln/SNYK-PYTHON-GUNICORN-6615672
- https://snyk.io/vuln/SNYK-PYTHON-SETUPTOOLS-3180412
- https://snyk.io/vuln/SNYK-PYTHON-WERKZEUG-6035177
- https://snyk.io/vuln/SNYK-PYTHON-WERKZEUG-6808933

requirements.txt

@@ -1,9 +1,11 @@
-cryptography==3.4.6
-Flask==2.0.3
-gevent==21.8.0
-gunicorn==20.1.0
+cryptography==42.0.8
+Flask==2.2.5
+gevent==23.9.0
+gunicorn==22.0.0
 OwnCA>=0.3.0
 pyOpenSSL==21.0.0
 pytest==6.2.5
 pytest-cov==3.0.0
 pytest-order==1.0.0
+setuptools>=65.5.1 # not directly required, pinned by Snyk to avoid a vulnerability
+werkzeug>=3.0.3 # not directly required, pinned by Snyk to avoid a vulnerability