Add a with_config decorator to comply with typing spec

[Viicos]

May fix #8514, as suggested in a comment.

If accepted, better documentation will follow

Selected Reviewer: @dmontagu

[codspeed-hq]

CodSpeed Performance Report

Merging #8611 will not alter performance

_{Comparing Viicos:with-config-decorator (7daacab) with main (2792775)}

Summary

✅ 10 untouched benchmarks

[sydney-runkle]

Hey @Viicos,

@dmontagu and I really like this approach. A few notes:

It'd be great if this could also be used with dataclasses. I think as it stands, it can, but you just haven't documented it yet. A few requests for changes (I know you wanted to get this approved before working on additional docs):

1. Docs update with a vanilla example for both dataclass and TypedDict. Docs in both the "Concepts" section and "API Documentation" section (via docstrings) would be fantastic.
2. mypy tests with this new decorator, as a proof of concept for how this fixes the original issue.

Thanks a bunch for your work on this - it'll be a great feature to have :).

[Viicos]

Please review

[sydney-runkle]

@Viicos,

Changes look great. I've requested two small docs updates. Additionally, looks like the mypy test isn't working properly. Could you please update that when you have a chance?

Other than that, looks good to go! Thanks!

[sydney-runkle]

@Viicos,

I've moved the attached issue into the 2.7.0 milestone :).

[sydney-runkle]

@Viicos,

Amazing work 🚀. Merging this now to be included in 2.7.0!