devel/py-wait-for2: New port: Handle simultaneous cancellation and future completion

Alternate implementation of asyncio.wait_for(). It handles several edge
cases like simultaneous cancellation of wait and completion of future
differently and consistently across Python versions 3.7+.
https://github.com/Traktormaster/wait-for2

Required for www/py-nicegui 2.18.0.

PR: 287082