fix: dev-requirements.txt to reduce vulnerabilities

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-CERTIFI-3164749
- https://snyk.io/vuln/SNYK-PYTHON-CERTIFI-5805047
- 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-JINJA2-6150717
- https://snyk.io/vuln/SNYK-PYTHON-REQUESTS-5595532
- https://snyk.io/vuln/SNYK-PYTHON-RSA-1038401
- https://snyk.io/vuln/SNYK-PYTHON-RSA-570831
- https://snyk.io/vuln/SNYK-PYTHON-WERKZEUG-3319935
- https://snyk.io/vuln/SNYK-PYTHON-WERKZEUG-3319936

dev-requirements.txt

@@ -6,4 +6,10 @@ httpretty==0.9.7
 parameterized==0.8.1
 pytest-cov
 pytest-ckan
-six>=1.13.0
+six>=1.13.0
+certifi>=2023.7.22 # not directly required, pinned by Snyk to avoid a vulnerability
+cryptography>=42.0.2 # not directly required, pinned by Snyk to avoid a vulnerability
+jinja2>=3.1.3 # not directly required, pinned by Snyk to avoid a vulnerability
+requests>=2.31.0 # not directly required, pinned by Snyk to avoid a vulnerability
+rsa>=4.7 # not directly required, pinned by Snyk to avoid a vulnerability
+werkzeug>=2.2.3 # not directly required, pinned by Snyk to avoid a vulnerability