fix: Use flutter build ios instead of ipa for CI builds

flutter build ipa requires a Development Team even with --no-codesign,
causing CI failures. Switch to flutter build ios --no-codesign which
builds without requiring provisioning.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: rmi22186

.github/workflows/pull-request.yml

@@ -107,17 +107,9 @@ jobs:
       - name: Test
         working-directory: example
         run: flutter test
-      - name: Build unsigned example Xcode archive
+      - name: Build unsigned example iOS app
         working-directory: example
-        run: flutter build ipa --no-codesign
-      - name: Check if unsigned example Xcode archive exists
-        working-directory: example
-        run: |
-          set -e
-          if [ ! -d build/ios/archive/Runner.xcarchive ]; then
-            echo "Xcode archive not found!"
-            exit 1
-          fi
+        run: flutter build ios --no-codesign
       - name: Cleanup
         if: ${{ always() }}
         working-directory: example

.github/workflows/release-from-main.yml

@@ -75,9 +75,9 @@ jobs:
       - name: Install example dependencies
         working-directory: example
         run: flutter pub get
-      - name: Build unsigned Xcode archive
+      - name: Build unsigned iOS app
         working-directory: example
-        run: flutter build ipa --no-codesign
+        run: flutter build ios --no-codesign
 
   setup-and-version:
     needs: [build-android, build-ios]