[eas-cli] parse request body for error only when needed

[kadikraman]

Why

Fixes a regression I introduced in https://github.com/expo/eas-cli/pull/2771/files
Successful deployments error because the body is already parsed.

How

Only parse the request body when to show the error message when needed.

Test Plan

Ensure eas deploy works without errors.

[github-actions]

Subscribed to pull request

File Patterns	Mentions
**/*	@szdziedzic, @khamilowicz, @sjchmiela, @radoslawkrzemien

Generated by CodeMention

[github-actions]

Size Change: -3.79 kB (-0.01%)

Total Size: 53.4 MB

Filename	Size	Change
./packages/eas-cli/dist/eas-linux-x64.tar.gz	53.4 MB	-3.79 kB (-0.01%)

_{compressed-size-action}

[github-actions]

✅ Thank you for adding the changelog entry!

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 5 lines in your changes missing coverage. Please review.

Project coverage is 52.51%. Comparing base (2a96d04) to head (102475b).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
packages/eas-cli/src/worker/upload.ts	0.00%	5 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2784      +/-   ##
==========================================
- Coverage   52.51%   52.51%   -0.00%     
==========================================
  Files         583      583              
  Lines       22581    22582       +1     
  Branches     4452     4452              
==========================================
  Hits        11856    11856              
- Misses      10690    10691       +1     
  Partials       35       35              

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