Lint issue fixed

Author: humitos

readthedocs/config/config.py

@@ -309,7 +309,7 @@ def get_valid_python_versions(self):
             return self.env_config['python']['supported_versions']
         except (KeyError, TypeError):
             versions = set()
-            for name, options in DOCKER_IMAGE_SETTINGS.items():
+            for _, options in DOCKER_IMAGE_SETTINGS.items():
                 versions = versions.union(options['python']['supported_versions'])
             return versions