Only run audit on dependencies

Fixes an issue where the audit was failing CI due to pip having a
vulnerability. pip is not a dependency for jsonschema.

Change the audit step to only check vulnerabilities in dependencies.

Author: gudnimg

noxfile.py

@@ -104,7 +104,7 @@ def audit(session, installable):
     Audit dependencies for vulnerabilities.
     """
     session.install("pip-audit", installable)
-    session.run("python", "-m", "pip_audit")
+    session.run("python", "-m", "pip_audit", "-r", str(REQUIREMENTS["docs"]))
 
 
 @session()