gh-102660: Fix Refleaks in import.c (#102744)

gh-102661 introduced some leaks. This fixes them.

https://github.com/python/cpython/issues/102660

Python/sysmodule.c

@@ -3425,9 +3425,6 @@ _PySys_Create(PyThreadState *tstate, PyObject **sysmod_p)
         return _PyStatus_ERR("failed to create a module object");
     }
 
-    /* m_copy of Py_None means it is copied some other way. */
-    sysmodule.m_base.m_copy = Py_NewRef(Py_None);
-
     PyObject *sysdict = PyModule_GetDict(sysmod);
     if (sysdict == NULL) {
         goto error;