Fix erroneous pylint errors

Author: adamtheturtle

pyproject.toml

@@ -68,6 +68,12 @@
         'duplicate-code',
         # Let isort handle imports
         'wrong-import-order',
+
+        # Wait until pylint supports Python 3.9 to disable these:
+        # - https://github.com/PyCQA/pylint/issues/3876
+        # - https://github.com/PyCQA/pylint/issues/3882
+        'unsubscriptable-object',
+        'inherit-non-class',
     ]
 
     [tool.pylint.'FORMAT']