gh-115775: Add whatsnew entry about __static_attributes__

[iritkatriel]

• Issue: Use static analysis to assist inlining values and compact object layout. #115775

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📚 Documentation preview 📚: https://cpython-previews--117909.org.readthedocs.build/

[encukou]

Thanks for the description!

I'm not sure what the use case is for adding this as public API. But since it is exposed, I guess it should also be added to the list of special attributes.

(Sorry about the drip-feed of suggestions :( I'm not following the change closely -- I'm just reacting to the effect on projects tested with the latest alpha.)

[encukou]

AFAIK, the missing definition should be added like this: iritkatriel#57

[encukou]

Thank you!