Linux EAS runners don't ship Ruby/Bundler, so `bundle install`
fails with "bundle: command not found". macOS workflow runners
have Ruby 3.2 + Fastlane preinstalled, so switching this job to
runs_on: macos-medium gets us there without a manual install step.
The eas/checkout step already cd's into packages/app (where eas.json
lives), so the explicit `working_directory: ./packages/app` on the
Fastlane steps resolved to /home/expo/workingdir/build/packages/app/packages/app
and failed every release with ENOENT.
Adds a fastlane lane and an EAS Workflow custom job that runs after
submit_ios. Picks up the latest TestFlight build, waits for Apple
processing, and submits for review with auto-release on approval.
Uses ASC_KEY_ID, ASC_ISSUER_ID, ASC_KEY_P8 secrets from the EAS
production environment.
Mohamed Boudra