x11-toolkits/py-xlib: Update 0.21 -> 0.23-4

I am updating to 0.23-4 because of this bug https://github.com/python-xlib/python-xlib/issues/121
It renders py-xlib broken on all systems with UNIX socket X11 DISPLAY, which is often/always a default.

PR: 229872
Approved by: Eero Hänninen <fax@nohik.ee> (maintainer)