Remove unused _PyModule_ExactDealloc in header file

Author: aisk

Include/internal/pycore_moduleobject.h

@@ -13,7 +13,6 @@ extern "C" {
 
 extern void _PyModule_Clear(PyObject *);
 extern void _PyModule_ClearDict(PyObject *);
-extern void _PyModule_ExactDealloc(PyObject *);
 extern int _PyModuleSpec_IsInitializing(PyObject *);
 extern int _PyModuleSpec_GetFileOrigin(PyObject *, PyObject **);
 extern int _PyModule_IsPossiblyShadowing(PyObject *);