Activate 'warn_unused_ignores' mypy check

Author: schnellerhase

pyproject.toml

@@ -70,7 +70,7 @@ disallow_any_unimported = false
 no_implicit_optional = false
 check_untyped_defs = false
 warn_return_any = false
-warn_unused_ignores = false
+warn_unused_ignores = true
 show_error_codes = true
 
 [[tool.mypy.overrides]]