fix: requirements_dev.txt to reduce vulnerabilities

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-CRYPTOGRAPHY-7886970

requirements_dev.txt

@@ -6,7 +6,7 @@ flake8==2.4.1
 tox==2.1.1
 coverage==4.0
 Sphinx==1.3.1
-cryptography==42.0.8
+cryptography==43.0.1
 tabulate==0.8.2
 configparser
 jinja2>=3.1.4 # not directly required, pinned by Snyk to avoid a vulnerability