bpo-33012: Fix invalid function cast warnings with gcc 8 for METH_NOARGS. (GH-6030)

METH_NOARGS functions need only a single argument but they are cast
into a PyCFunction, which takes two arguments.  This triggers an
invalid function cast warning in gcc8 due to the argument mismatch.
Fix this by adding a dummy unused argument.

Modules/_io/winconsoleio.c

@@ -1057,7 +1057,7 @@ _io__WindowsConsoleIO_isatty_impl(winconsoleio *self)
 }
 
 static PyObject *
-winconsoleio_getstate(winconsoleio *self)
+winconsoleio_getstate(winconsoleio *self, PyObject *Py_UNUSED(ignored))
 {
     PyErr_Format(PyExc_TypeError,
                  "cannot serialize '%s' object", Py_TYPE(self)->tp_name);