fix: Add setuptools to lint_setup_py session

Author: chalmerlowe

noxfile.py

@@ -157,7 +157,7 @@ def mypy(session):
 @nox.session(python=DEFAULT_PYTHON_VERSION)
 def lint_setup_py(session):
     """Verify that setup.py is valid (including RST check)."""
-    session.install("docutils", "pygments")
+    session.install("docutils", "pygments", "setuptools")
     session.run("python", "setup.py", "check", "--restructuredtext", "--strict")