fix: Fix invalid list collection in expression engine

[ritchie46]

fixes #19173

Also makes get_list_builder work for Object types and thus is now infallible.

I can get rid of the extra if len == 0 branch, but must fix some IR bugs to do that. Will follow up.

[codecov]

Codecov Report

Attention: Patch coverage is 87.30159% with 8 lines in your changes missing coverage. Please review.

Project coverage is 79.66%. Comparing base (f8a7041) to head (758a016).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
crates/polars-expr/src/expressions/apply.rs	68.00%	8 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #19191      +/-   ##
==========================================
- Coverage   79.67%   79.66%   -0.02%     
==========================================
  Files        1532     1532              
  Lines      209150   209132      -18     
  Branches     2416     2416              
==========================================
- Hits       166648   166598      -50     
- Misses      41956    41988      +32     
  Partials      546      546              

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