fix: Fix bug where alias was ignored in COUNT(*) optimization

[c-peters]

The alias was ignored in the optimization which lead to schema mismatches between optimized and non-optimized.

[codecov]

Codecov Report

Attention: Patch coverage is 98.63014% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 81.06%. Comparing base (d4ee7a7) to head (0f06cd6).
Report is 1 commits behind head on main.

Files	Patch %	Lines
...lars-plan/src/logical_plan/optimizer/count_star.rs	98.50%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #14738   +/-   ##
=======================================
  Coverage   81.06%   81.06%           
=======================================
  Files        1322     1322           
  Lines      171364   171395   +31     
  Branches     2461     2461           
=======================================
+ Hits       138910   138944   +34     
+ Misses      31983    31981    -2     
+ Partials      471      470    -1     

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