[yaml] - add yaml expand_pipeline ut tests

[derrickaw]

#36086

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[derrickaw]

Run Python_Transforms PreCommit 3.12

[derrickaw]

Run Python_Transforms PreCommit 3.11

[derrickaw]

Run Yaml_Xlang_Direct PreCommit

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 54.91%. Comparing base (32f5be6) to head (6f468f3).
⚠️ Report is 4 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff            @@
##             master   #36087   +/-   ##
=========================================
  Coverage     54.91%   54.91%           
  Complexity     1617     1617           
=========================================
  Files          1057     1057           
  Lines        164007   164007           
  Branches       1165     1165           
=========================================
+ Hits          90066    90068    +2     
+ Misses        71788    71786    -2     
  Partials       2153     2153           

Flag	Coverage Δ
python	81.01% <ø> (+<0.01%)	⬆️

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[derrickaw]

Failure is due to #35981. Not related.

[derrickaw]

assign set of reviewers

[github-actions]

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R: @liferoad for label python.

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