[steps] Expand local actions at parse time

[sswrk]

Why

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How

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Test Plan

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[linear-code]

ENG-22387

[sswrk]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
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• [eas-cli] Validate local actions in workflow files #3931
• [build-tools] Load local action catalog at build runtime #3930
• [steps] Expand local actions at parse time #3929 👈 (View in Graphite)
• [steps] Add local action discovery utilities #3956
• [eas-build-job] Add local action schema #3928
• main

This stack of pull requests is managed by Graphite. Learn more about stacking.

[codecov]

Codecov Report

❌ Patch coverage is 95.01916% with 13 lines in your changes missing coverage. Please review.
✅ Project coverage is 59.54%. Comparing base (c230ee8) to head (4de54ff).

Files with missing lines	Patch %	Lines
packages/steps/src/utils/actionInterpolation.ts	91.47%	7 Missing ⚠️
packages/steps/src/ActionExpander.ts	97.23%	3 Missing and 1 partial ⚠️
packages/steps/src/StepsConfigParser.ts	94.45%	1 Missing ⚠️
packages/steps/src/utils/step.ts	92.31%	1 Missing ⚠️

Additional details and impacted files

@@                                   Coverage Diff                                   @@
##           szymonswierk/eng-22387-steps-local-action-discovery    #3929      +/-   ##
=======================================================================================
+ Coverage                                                59.33%   59.54%   +0.22%     
=======================================================================================
  Files                                                      937      940       +3     
  Lines                                                    41154    41397     +243     
  Branches                                                  8671     8746      +75     
=======================================================================================
+ Hits                                                     24414    24646     +232     
- Misses                                                   16646    16656      +10     
- Partials                                                    94       95       +1     

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[github-actions]

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