Fix test case

Author: cdce8p

mypy/test/teststubtest.py

@@ -3135,7 +3135,6 @@ def test_get_typeshed_stdlib_modules(self) -> None:
         assert "os.path" in stdlib
         assert "asyncio" in stdlib
         assert "graphlib" not in stdlib
-        assert "formatter" in stdlib
         assert "contextvars" in stdlib  # 3.7+
         assert "importlib.metadata" not in stdlib