Fix test.

Author: ZeroIntensity

Modules/_testcapimodule.c

@@ -3490,7 +3490,7 @@ tracemalloc_track_race(PyObject *self, PyObject *args)
 static PyObject *
 is_immortal(PyObject *self, PyObject *op)
 {
-    return PyUnstable_IsImmortal(op);
+    return PyBool_FromLong(PyUnstable_IsImmortal(op));
 }
 
 static PyMethodDef TestMethods[] = {
@@ -3636,7 +3636,7 @@ static PyMethodDef TestMethods[] = {
     {"test_atexit", test_atexit, METH_NOARGS},
     {"code_offset_to_line", _PyCFunction_CAST(code_offset_to_line), METH_FASTCALL},
     {"tracemalloc_track_race", tracemalloc_track_race, METH_NOARGS},
-    {"is_immortal", is_immortal, METH_O}
+    {"is_immortal", is_immortal, METH_O},
     {NULL, NULL} /* sentinel */
 };