use FromPyObjectBound for PyAny::extract

[Icxolu]

This changes the bound of PyAny::extract to use FromPyObjectBound instead of FromPyObject. This allows extracting borrowed types like &str or &[u8] using the gil-ref API, even if the gil-refs feature is disabled.

To allow this, FromPyObjectBound::from_py_object_bound is switched to take a Borrowed instead of &Bound. This also means that the FromPyObjectBound implemetations can now be unconditionally. To not break fully qualified syntax (FromPyObject::extract) these are kept with gil-refs enabled.

Fixes #3958

[codspeed-hq]

CodSpeed Performance Report

Merging #3959 will not alter performance

_{Comparing Icxolu:extract (07386db) with main (989d2c5)}

Summary

✅ 67 untouched benchmarks

[davidhewitt]

Making PyAny::extract work the same way as the other .extract() methods seems like a good consistency change. Because FromPyObjectBound has a blanket from FromPyObject, I would hope that it means that users depending on FromPyObject as a trait bound in generic code wouldn't experience breaking changes.

[davidhewitt]

This looks good to me, thanks!