bugfix: fixes a test suite bug in the __new__ example (#4698)

* bugfix: fixes a test suite bug in the __new__ example

* See https://github.com/pybind/pybind11/pull/4698#discussion_r1227107682

---------

Co-authored-by: Ralf W. Grosse-Kunstleve <rwgk@google.com>
1 file changed