Use PyType_Check() instead of direct comparison with PyType_Type pointer.

Context:

* pybind/pybind11#4427 (comment)

> I don't think your logic ... is actually correct? I don't think it would handle metaclasses right.

PiperOrigin-RevId: 498690703

Author: rwgk

clif/python/runtime.cc

@@ -157,15 +157,15 @@ PyObject* ImportFQName(const std::string& full_class_name,
 
 // py.__class__.__name__
 const char* ClassName(PyObject* py) {
-  if (Py_TYPE(py) == &PyType_Type) {
+  if (PyType_Check(py)) {
     return reinterpret_cast<PyTypeObject*>(py)->tp_name;
   }
   return Py_TYPE(py)->tp_name;
 }
 
 // type(py) renamed from {classobj, instance, type, class X}
 const char* ClassType(PyObject* py) {
-  if (Py_TYPE(py) == &PyType_Type) {
+  if (PyType_Check(py)) {
     return "class";
   }
   return "instance";