feat: Add ignore_nulls to {list,arr}.{any,all}

[coastalwhite]

Fixes #16764.

This PR dispatches {list,arr}.{any,all} to
{list,arr}.agg(pl.element().{any,all}() removing a bunch of code and giving us the ignore_nulls flag for free. This still should be efficient (although maybe a tiny bit more memory), as this will go through the group aggregation evaluation engine.

No AI was used.

[codecov]

Codecov Report

❌ Patch coverage is 88.23529% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 81.71%. Comparing base (7eb80ee) to head (32c556b).
⚠️ Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
crates/polars-plan/src/dsl/expr/mod.rs	50.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #27186      +/-   ##
==========================================
+ Coverage   80.85%   81.71%   +0.85%     
==========================================
  Files        1816     1814       -2     
  Lines      250589   250439     -150     
  Branches     3147     3147              
==========================================
+ Hits       202618   204649    +2031     
+ Misses      47166    44985    -2181     
  Partials      805      805              

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[ritchie46]

Seems good to me. I'd rather improve the generic path performance indeed. We need to wait merging until we can break DSL.

[orlp]

Just for my sanity, the generic list aggregation path is marked as elementwise, right?

[coastalwhite]

Just for my sanity, the generic list aggregation path is marked as elementwise, right?

Indeed, {list,arr}.{eval,agg} are all always elementwise, regardless of their evaluation expression.