fix: Raise invalid predicate join_where

[ritchie46]

fixes #18745

[codecov]

Codecov Report

Attention: Patch coverage is 92.00000% with 2 lines in your changes missing coverage. Please review.

Project coverage is 79.87%. Comparing base (ab5200d) to head (4ebc8a4).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...ates/polars-plan/src/plans/conversion/dsl_to_ir.rs	50.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #19020      +/-   ##
==========================================
+ Coverage   79.85%   79.87%   +0.01%     
==========================================
  Files        1524     1524              
  Lines      207734   207749      +15     
  Branches     2908     2908              
==========================================
+ Hits       165891   165939      +48     
+ Misses      41294    41261      -33     
  Partials      549      549              

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