Polars: py-0.15.1 Release

⚠️ Breaking changes

• Update Expr.sample signature and change random seeding (#4648)
• rollup breaking changes (#5602)
• iso weekday (#5598)
• Change null_equal default to True for Series.series_equal (#5051)
• rollup breaking changes (#5602)

🚀 Performance improvements

• fix quadratic time complexity of groupby in stream… (#5614)
• Improve performance of indexing operations on Series. (#5610)
• Aggregate projection pushdown (#5556)

✨ Enhancements

• add a cache to strptime (#5628)
• add nearest interpolation strategy (#5626)
• Update Expr.sample signature and change random seeding (#4648)
• Change null_equal default to True for Series.series_equal (#5051)
• make cast recursive (#5596)
• add arg_min/arg_max for series of dtype boolean (#5592)

🐞 Bug fixes

• early error on duplicate names in streaming groupby (#5638)
• fix streaming groupby aggregate types (#5636)
• convert panic to err in concat_list (#5637)
• fix dot diagram of single nodes (#5624)
• fix dynamic struct inference (#5619)
• tz-aware filtering (#5603)
• keep dtype when eval on empty list (#5597)
• fix ternary with list output on empty frame (#5595)
• fix tz-awareness of truncate (#5591)
• check chunks before doing chunked_id join optimiza… (#5589)
• invert cast_time_zone conversion (#5587)
• asof join ensure join column is not dropped when '… (#5585)

🛠️ Other improvements

• Remaining docstring examples for frame and lazyframe (#5630)
• use xxhash3 for string types (#5617)
• only trigger build.rs file if that file itself has cha… (#5618)
• iso weekday (#5598)
• Merge release workflows (#5564)
• Fix broken lint workflow (#5584)

Thank you to all our contributors for making this release possible! @Kuhlwein, @braaannigan, @ghuls, @matteosantama, @ritchie46 and @stinodego