pythongh-77560: Report possible errors in restoring builtins at final…

…ization

Seems in the past the copy of builtins was not made in some scenarios,
and the error was silenced. Write it now to stderr, so we have a chance
to see it.

Python/pylifecycle.c

@@ -1462,7 +1462,7 @@ finalize_restore_builtins(PyThreadState *tstate)
     }
     PyDict_Clear(interp->builtins);
     if (PyDict_Update(interp->builtins, interp->builtins_copy)) {
-        _PyErr_Clear(tstate);
+        PyErr_WriteUnraisable(NULL);
     }
     Py_XDECREF(dict);
 }