[doc] Clarify that Popen.wait is only a busy-loop in certain cases

Documentation

In the docs for Popen.wait(), it states:

Note The function is implemented using a busy loop (non-blocking call and short sleeps). Use the asyncio module for an asynchronous wait: see asyncio.create_subprocess_exec.

This is actually only true in a specific circumstance: when both using Posix/Unix and a timeout is given. If, on the other hand, no timeout is given, then it does not go into a busy-loop but instead blocks on os.waitpid(). And for Windows, it never goes into a busy-loop, as it uses the WaitForSingleObject() windows API.

This note in the docs caused me to refactor my code to use asyncio - only later did I actually check what python did internally and discovered the note was wrong.

Comienza con la documentación de Popen.wait() enlazada en el issue y compara la nota con el comportamiento de la plataforma y de timeout descrito aquí. Revisa la nota para que limite la afirmación sobre el bucle ocupado a las esperas POSIX/Unix con un timeout, y cubra correctamente los casos sin timeout y de Windows. Se considera terminado cuando la redacción sea técnicamente correcta y conserve las indicaciones sobre asyncio.