Attempt to silence MyPy

Author: markshannon

Tools/cases_generator/stack.py

@@ -730,5 +730,6 @@ def close_variable(var: Local, overwrite: str) -> None:
             var.defined = False
         if output is not None:
             output.defined = True
-            lowest.defined = False
+            # MyPy false positive
+            lowest.defined = False  # type: ignore
         self.flush(out)