Revert "fill __module__ attribute for built-in classmethods too"

This reverts commit c4dec10.

Author: skirpichev

Lib/test/test_funcattrs.py

@@ -474,9 +474,9 @@ def test_builtin__module__(self):
         self.assertEqual(decimal.Decimal.exp.__objclass__.__module__, 'decimal')
 
         # builtin classmethod:
-        self.assertEqual(int.from_bytes.__module__, 'builtins')
+        self.assertEqual(int.from_bytes.__module__, None)
         self.assertEqual(int.from_bytes.__self__.__module__, 'builtins')
-        self.assertEqual(decimal.Decimal.from_float.__module__, 'decimal')
+        self.assertEqual(decimal.Decimal.from_float.__module__, None)
         self.assertEqual(decimal.Decimal.from_float.__self__.__module__, 'decimal')
 
         # builtin staticmethod:

Misc/NEWS.d/next/Core_and_Builtins/2024-02-10-05-42-26.gh-issue-115231.6T7dzi.rst

@@ -1,2 +1,2 @@
-Setup ``__module__`` attribute for built-in class/static methods.  Patch by
-Sergey B Kirpichev.
+Setup ``__module__`` attribute for built-in static methods.  Patch by Sergey
+B Kirpichev.

Objects/descrobject.c

@@ -131,11 +131,7 @@ classmethod_get(PyObject *self, PyObject *obj, PyObject *type)
     if (descr->d_method->ml_flags & METH_METHOD) {
         cls = descr->d_common.d_type;
     }
-    PyObject *mod = PyObject_GetAttr((PyObject*)type, &_Py_ID(__module__));
-    PyErr_Clear();
-    PyObject *result = PyCMethod_New(descr->d_method, type, mod, cls);
-    Py_XDECREF(mod);
-    return result;
+    return PyCMethod_New(descr->d_method, type, NULL, cls);
 }
 
 static PyObject *