[release-20.0-rc] fix: order by subquery planning (#16049)

[vitess-bot]

Description

This is a backport of #16049

[vitess-bot]

Review Checklist

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[codecov]

Codecov Report

Attention: Patch coverage is 60.76555% with 82 lines in your changes missing coverage. Please review.

Project coverage is 68.43%. Comparing base (965da11) to head (f8624a2).
Report is 3 commits behind head on release-20.0-rc.

Files	Patch %	Lines
go/vt/sqlparser/ast.go	5.00%	38 Missing ⚠️
.../vt/vtgate/planbuilder/operators/query_planning.go	58.97%	16 Missing ⚠️
go/vt/vtgate/planbuilder/operators/subquery.go	33.33%	10 Missing ⚠️
go/vt/vtgate/planbuilder/operators/aggregator.go	80.00%	5 Missing ⚠️
go/vt/vtgate/planbuilder/operators/projection.go	71.42%	4 Missing ⚠️
.../vtgate/planbuilder/operators/subquery_planning.go	80.95%	4 Missing ⚠️
.../vtgate/planbuilder/operators/horizon_expanding.go	88.46%	3 Missing ⚠️
go/vt/sqlparser/ast_funcs.go	80.00%	1 Missing ⚠️
...vtgate/planbuilder/operators/subquery_container.go	83.33%	1 Missing ⚠️

Additional details and impacted files

@@                 Coverage Diff                 @@
##           release-20.0-rc   #16133      +/-   ##
===================================================
+ Coverage            68.24%   68.43%   +0.19%     
===================================================
  Files                 1541     1541              
  Lines               197330   198905    +1575     
===================================================
+ Hits                134665   136119    +1454     
- Misses               62665    62786     +121     

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