Remove local project generation from go command

[tchayen]

Why

The go command creates a full local project in /tmp (writes app.json, eas.json, package.json, runs npm install, git init, git commit) solely to satisfy the credentials setup and produce files for the workflow upload. This is unnecessary overhead — credentials operate entirely through remote APIs and the workflow can generate its own project.

This is a step toward having the workflow create its own project server-side, removing the dependency on user-uploaded project files.

How

• In-memory ExpoConfig: Construct the exp object directly instead of writing app.json to disk and reading it back with getPrivateExpoConfigAsync
• No-op VcsClient: Pass NoVcsClient to CredentialsContext since none of the iOS credential actions (SetUpBuildCredentials, SetUpAscApiKey, SetUpPushKey) use it
• No npm install / git init: The workflow doesn't need node_modules or a git repo
• Direct tarball creation: Use tar.create() on a minimal temp directory instead of going through VCS-based uploadAccountScopedProjectSourceAsync
• No process.chdir(): Removed the process.chdir(projectDir) / restore pattern entirely
• Removed saveProjectIdToAppConfigAsync: Project ID is kept in-memory, no need to write it to disk
• Minimal upload files: Only creates temp files (eas.json with ascAppId, package.json, app.json) right before upload, then cleans up immediately

Test Plan

• Verify yarn tsc --noEmit passes for go.ts (confirmed: no type errors)
• Verify yarn lint passes (confirmed: no lint issues)
• Manual test: run eas go and verify credentials setup + workflow trigger still work

[github-actions]

Subscribed to pull request

File Patterns	Mentions
**/*	@douglowder

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[github-actions]

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[codecov]

Codecov Report

❌ Patch coverage is 10.71429% with 50 lines in your changes missing coverage. Please review.
✅ Project coverage is 53.65%. Comparing base (d5a3fc0) to head (822b703).
⚠️ Report is 12 commits behind head on main.

Files with missing lines	Patch %	Lines
packages/eas-cli/src/commands/go.ts	10.72%	50 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3514      +/-   ##
==========================================
+ Coverage   53.56%   53.65%   +0.09%     
==========================================
  Files         815      815              
  Lines       34566    34616      +50     
  Branches     7175     7193      +18     
==========================================
+ Hits        18513    18570      +57     
+ Misses      15971    15965       -6     
+ Partials       82       81       -1     

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