Build fails with pybind11 3.0.0

Our build fails for python >=3.11 with pybind11 3.0.0: https://gitlab.com/tango-controls/pytango/-/jobs/10671972312#L570

The reason in that in python 3.11 PyCFunction_GET_SELF was converted from macro to inlined function: https://peps.python.org/pep-0670/ and now it is copied to our code and expands here.

I found out, that this happens after this pybind11 PR: https://github.com/pybind/pybind11/pull/5580 , but, actually, I cannot explain why and how.

Unfortunately I do not know any way to fight against warnings in inlined functions :-( So it seems we have to disable the -Wnull-dereference flag, which is a pity :-(