[3.13] gh-128100: Use atomic dictionary load in _PyObject_GenericGetAttrWithDict (GH-128297) (GH-129979)

(cherry picked from commit 47d2cb8eb7)

Co-authored-by: Bogdan Romanyuk <65823030+wrongnull@users.noreply.github.com>

Objects/object.c

@@ -1692,7 +1692,11 @@ _PyObject_GenericGetAttrWithDict(PyObject *obj, PyObject *name,
         else {
             PyObject **dictptr = _PyObject_ComputedDictPointer(obj);
             if (dictptr) {
+#ifdef Py_GIL_DISABLED
+                dict = _Py_atomic_load_ptr_acquire(dictptr);
+#else
                 dict = *dictptr;
+#endif
             }
         }
     }