bpo-35414: Add a missing Py_INCREF(Py_None) in PyState_RemoveModule(). (GH-10914)

(cherry picked from commit 2a89343)

Co-authored-by: Zackery Spytz <zspytz@gmail.com>

Author: miss-islington

Python/pystate.c

@@ -532,6 +532,7 @@ PyState_RemoveModule(struct PyModuleDef* def)
         Py_FatalError("PyState_RemoveModule: Module index out of bounds.");
         return -1;
     }
+    Py_INCREF(Py_None);
     return PyList_SetItem(state->modules_by_index, index, Py_None);
 }