chore(python): More PyO3 0.21 Bound<> APIs, and finally disable gil-refs backwards compat feature on pyo3 crate

[itamarst]

Fixes #16142

Note that I am not convinced we've caught all usages of the old reference-style code (&PyAny and friends instead of Bound<PyAny>). Not everything is quite deprecated yet, is my impression. I have supplemented explicit warnings with some grepping, but still. But, presumably this will get caught as newer PyO3 releases come out.

[codecov]

Codecov Report

Attention: Patch coverage is 86.25000% with 11 lines in your changes are missing coverage. Please review.

Project coverage is 81.00%. Comparing base (c4e8678) to head (95dbf53).
Report is 33 commits behind head on main.

Files	Patch %	Lines
py-polars/src/map/dataframe.rs	0.00%	5 Missing ⚠️
py-polars/src/map/lazy.rs	66.66%	3 Missing ⚠️
py-polars/src/conversion/mod.rs	95.55%	2 Missing ⚠️
py-polars/src/datatypes.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #16143      +/-   ##
==========================================
+ Coverage   80.96%   81.00%   +0.04%     
==========================================
  Files        1386     1392       +6     
  Lines      178437   178916     +479     
  Branches     2882     2901      +19     
==========================================
+ Hits       144463   144923     +460     
- Misses      33480    33488       +8     
- Partials      494      505      +11     

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[ritchie46]

I have supplemented explicit warnings with some grepping, but still. But, presumably this will get caught as newer PyO3 releases come out.

Isn't there a feature flag that prohibits the old style usage?

[itamarst]

Docs just say "As a final step of migration, deactivating the gil-refs feature will set up code for best performance and is intended to set up a forward-compatible API for PyO3 0.22." and there's nothing at https://docs.rs/crate/pyo3/latest/features. So no extra flag we can set.

However, most even if not all usages of the old API will have a deprecation warning message now that gil-refs feature is disabled.

[itamarst]

@ritchie46 back to you.

[ritchie46]

Alright! thanks for this one @itamarst. Great to be up to date and hopefully we'll have some perf benefits out of it.

It is at least much clearer where the cost is now, so once we can drop py38, we'll do another pass.