Dont use __init__

Given recent precompilation concerns it would be better not to use and recommend using `__init__` here.

Instead pynew() could have a runtime value check, and do the import automatically on the first call?

We could pass it a string for the module name, or a closure.

Start by reviewing the issue's discussion around `__init__` and the `pynew()` entry point, focusing on the precompilation concern and the proposed runtime value check. The work is complete when the intended import behavior and accepted module-name or closure interface are defined and implemented, with validation for the first call.

Scritto dal modello di indicizzazione a partire dal testo della issue.