Python Polars 0.19.18

✨ Enhancements

• support nested null in vstack/append/extend/concat (#12771)
• Improve error messages on attempted Arrow conversions involving incompatible/unknown dtypes (#12421)
• determine mode parallelism depending on current tasks (#12764)
• enable slice push down past with_columns (#12742)
• Improve write_database, accounting for latest adbc fixes/updates (#12713)

🐞 Bug fixes

• don't use streaming engine if aggregate is unknown (#12769)
• Enable special casing of sequence in list_to_struct (#12759)
• hold align_chunks_invariant (#12738)
• allow leading zero and plus in integer parsing (#12744)
• csv lines iter, always return remainder (#12739)
• fix oob in set operations (#12736)
• undo regression in ability to read certain parquet files (#12731)

🛠️ Other improvements

• Use latest atoi_simd release (#12748)
• Fix invalid references to xlsx2csv dependency (#12741)
• Remove pinned aiohttp dependency (#12733)

Thank you to all our contributors for making this release possible!
@0siride, @PierreAttard, @RoDmitry, @alexander-beedie, @dependabot, @dependabot[bot], @eitsupi, @kszlim, @nameexhaustion, @orlp, @ritchie46 and @stinodego