Fix issues with version

[mattdangerw]

Maybe better ways to do this, but a few issues with the version() util we added.

• For nightly packages we were re-writing __version__ in __init__.py, which would not affect the version() util. So for nightlies keras_nlp.__version__ != keras_nlp.version().
• We try to keep the local editable install equivalent to the exported paths where possible. But before this change keras_nlp.version is a file module locally, and a function after building the package.

[grasskin]

LGTM thank you! Although I think for future-proofing we might want to take a stronger stance on letting the API diverge from the editable version or just disable that option (namex path checks?)

[mattdangerw]

LGTM thank you! Although I think for future-proofing we might want to take a stronger stance on letting the API diverge from the editable version or just disable that option (namex path checks?)

Fair point, I would just really miss the ability to do an editable install. Legitimately much faster if you want to quickly iterate on something outside of unit testing.