perf: Fix pathologic rolling + group-by performance and memory explosion

[ritchie46]

fixes #18525

[codecov]

Codecov Report

Attention: Patch coverage is 96.55172% with 5 lines in your changes missing coverage. Please review.

Project coverage is 79.89%. Comparing base (237b506) to head (741e66d).
Report is 3 commits behind head on main.

Files with missing lines	Patch %	Lines
.../polars-arrow/src/legacy/kernels/sort_partition.rs	89.47%	4 Missing ⚠️
...olars-mem-engine/src/executors/group_by_rolling.rs	96.96%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #21403      +/-   ##
==========================================
- Coverage   79.95%   79.89%   -0.07%     
==========================================
  Files        1597     1597              
  Lines      228954   229027      +73     
  Branches     2618     2618              
==========================================
- Hits       183069   182981      -88     
- Misses      45286    45447     +161     
  Partials      599      599              

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[github-actions]

The uncompressed lib size after this PR is 41.6219 MB.