modify generate api.spec (#24503)

tools/print_signatures.py

@@ -105,6 +105,8 @@ def visit_member(parent_name, member):
             if hasattr(value, '__name__') and (not name.startswith("_") or
                                                name == "__init__"):
                 visit_member(cur_name, value)
+    elif inspect.ismethoddescriptor(member):
+        return
     elif callable(member):
         queue_dict(member, cur_name)
     elif inspect.isgetsetdescriptor(member):