[eas-cli] Validate custom actions in workflow files

[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 custom actions in workflow files #3931 👈 (View in Graphite)
• [build-tools] Load custom action catalog at build runtime #3930
• [steps] Expand custom actions at parse time #3929
• [eas-build-job] Add custom action schema and utils #3928
• main

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[github-actions]

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⏩ If this PR doesn't require a changelog entry, such as if it's an internal change that doesn't affect the user experience, you can add the "no changelog" label to the PR.

[codecov]

Codecov Report

❌ Patch coverage is 90.00000% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 59.57%. Comparing base (d95f9f7) to head (23c7c61).

Files with missing lines	Patch %	Lines
...es/eas-cli/src/commandUtils/workflow/validation.ts	33.34%	2 Missing ⚠️
...kages/eas-cli/src/commandUtils/workflow/actions.ts	96.30%	1 Missing ⚠️

Additional details and impacted files

@@                                               Coverage Diff                                               @@
##           szymonswierk/eng-22387-build-tools-load-custom-action-catalog-at-build-time    #3931      +/-   ##
===============================================================================================================
+ Coverage                                                                        59.55%   59.57%   +0.03%     
===============================================================================================================
  Files                                                                              940      941       +1     
  Lines                                                                            41415    41445      +30     
  Branches                                                                          8743     8745       +2     
===============================================================================================================
+ Hits                                                                             24660    24687      +27     
- Misses                                                                           16661    16664       +3     
  Partials                                                                            94       94              

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