Don't autoregister extensions

[MarcoGorelli]

xref pola-rs/polars#13899

Things I love:

• plugins

Things I don't love:

• imports with side-effects
• breaking static typing
• breaking linting

---

This doesn't remove any functionality. The only difference is that if you want the expressions extension, you need to do

import expression_lib.extension  # noqa: F401

to activate it.

Otherwise, you will just have to use the functions directly, e.g.

    dist.jaccard_similarity("dist_a", "dist_b")

instead of

    pl.col("dist_a").dist.jaccard_similarity("dist_b")

[ritchie46]

I understand. Though I want to be ambivalent about it. Let's show both. :)

[MarcoGorelli]

sure thing - I'm now showing both in both run.py and README.md