fix: requirements/requirements.lint.txt to reduce vulnerabilities (#15)

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-SETUPTOOLS-3180412

Author: snyk-bot

requirements/requirements.lint.txt

@@ -7,3 +7,4 @@ pylint
 pyright
 validate-pyproject
 vulture
+setuptools>=65.5.1 # not directly required, pinned by Snyk to avoid a vulnerability