Polars: py-0.17.12 Release

🚀 Performance improvements

• add fused multiply add optimization for expressions (#8690)
• use expression for dot product (#8686)

✨ Enhancements

• streaming unions (#8676)
• allow arr.to_struct to take a list of field names, fix it for Series, improve related docstrings (#8673)
• expression cache (#8674)
• rolling covariance and correlation (#8671)
• .to_physical() for List(Categorical) (#8499)
• allow from_repr to handle parsing of table reprs with no dtype row (#8640)
• Add dt.to_string alias for dt.strftime (#8290)
• support DataFrame export to numpy structured/record arrays (#8628)
• support transparent DataFrame init from numpy structured/record arrays. (#8620)
• Prettify show_versions (#8627)

🐞 Bug fixes

• allow arr.to_struct to take a list of field names, fix it for Series, improve related docstrings (#8673)
• block predicate containing shifts and windows after sort (#8670)
• ensure perfect hash table processes the nulls (#8668)
• Reading more tiny CSVs than workers in parallel will deadlock (#8441)
• respect maintain_order in partitioned groupby (#8653)
• fix explode null series (#8654)
• fix categorical agg type (#8645)
• allow list<null> -> list<cat> (#8636)

🛠️ Other improvements

• add notes/examples on use of inline regex flags to replace docstrings (#8685)
• Add "See Also" sections for alias, map_alias, prefix, s… (#8682)
• add notes/examples on use of inline regex flags to extract_all docstrings (#8675)
• allow arr.to_struct to take a list of field names, fix it for Series, improve related docstrings (#8673)
• add notes on the use of inline regex flags to extract docstrings (#8669)
• Add missing implode to internal functions (#8667)
• Clean up type checking imports (#8666)
• Organize PySeries impl blocks (#8665)
• clean-up some examples, extend pipe docstring (#8658)
• add notes on the use of inline regex flags to contains docstrings (#8657)
• fix/improve from_repr example/doctest (#8642)
• Improve some bindings imports (#8630)
• Move functions in Rust bindings to functions module (#8629)
• only require typing_extensions before Python 3.8 (#8623)
• Set up separate modules for lazy classes (#8624)
• Remove duplicate util in Rust bindings (#8622)
• Move Python version to env in release workflow (#8621)

Thank you to all our contributors for making this release possible! @MarcoGorelli, @alexander-beedie, @dependabot, @dependabot[bot], @ghuls, @jonashaag, @josh, @mcrumiller, @ritchie46 and @stinodego