Remove an outdated comment. (GH-30010)

Author: serhiy-storchaka

Tools/clinic/clinic.py

@@ -2820,8 +2820,6 @@ def converter_init(self, *, accept={object}):
 
     def parse_arg(self, argname, displayname):
         if self.format_unit == 'i':
-            # XXX PyFloat_Check can be removed after the end of the
-            # deprecation in _PyLong_FromNbIndexOrNbInt.
             return """
                 {paramname} = _PyLong_AsInt({argname});
                 if ({paramname} == -1 && PyErr_Occurred()) {{{{