Fix fluwx CocoaPods CI to install pods before iOS build

[Copilot]

The iOS build — fluwx (CocoaPods) workflow was failing because the build path entered Xcode SwiftPM resolution instead of using the CocoaPods workspace. This updates the job to perform the same CocoaPods setup already used by the working fluwx_no_pay iOS job.

• Root cause

  • The fluwx CocoaPods workflow ran flutter build ios directly after flutter pub get.
  • In that path, Xcode attempted to resolve the local SwiftPM FlutterFramework package and failed on CI.

• Workflow change

  • Add pod install in packages/fluwx/example/ios before flutter build ios --no-codesign.
  • Align the fluwx CocoaPods job with the documented CocoaPods flow and the existing fluwx_no_pay CocoaPods job.

• Resulting job flow

  - name: Build fluwx example (CocoaPods)
    run: |
      cd packages/fluwx/example
      flutter pub get
      cd ios
      pod install
      cd ..
      flutter build ios --no-codesign