Do not run env check on lore import - only on cli invocation

[levkk]

What

import lore triggers environment setup which prevents modular use of Lore. Run the env check explicitly instead when lore entrypoint is called.

Why

This allows Lore to be used as a module for its internal functions without the environment setup which can be done by other means, e.g. Docker.

[montanalow]

One of the key value props is that lore guarantees the dependencies are correct across all the environments MLEs work in, from jupyter notebook investigations to training locally, at scale and during inference.

To use lore without that feature, you can:

import sys
sys.lore_no_env = True
import lore

It's not recommended, since it results in frequent production incidents as training/inference environments drift. Other dynamic languages like Ruby solve this problem with tools like Bundler. Since lore was created, PyPa has adopted Pipfile, but it has not become the standard complete replacement for pip, nor does it have the full functionality of Bundler. https://github.com/pypa/pipfile