fix: requirements.txt to reduce vulnerabilities

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-PARAMIKO-6130887

Author: snyk-bot

requirements.txt

@@ -13,3 +13,4 @@ rich==12.5.1
 setuptools>=65.5.1 # not directly required, pinned by Snyk to avoid a vulnerability
 tox
 yamllint==1.28.0
+paramiko>=3.4.0 # not directly required, pinned by Snyk to avoid a vulnerability