devel/py-pyro: deprecate and set to expire

Development of pyro4 stopped upstream. It's codebase isn't compatible
with Python 3.11 and later and will never be. Author recommends to switch
to pyro5 (not in ports) for new projects:

https://github.com/irmen/Pyro4?tab=readme-ov-file#pyro4---python-remote-objects