fix: combine Metro and app warmup into single step

Author: mfazekas

.github/workflows/ci.yml

@@ -268,14 +268,17 @@ jobs:
         run: |
           xcrun simctl install booted example/ios/build/Build/Products/Debug-iphonesimulator/RiveExample.app
 
-      - name: Debug - Test app launch
+      - name: Warmup - Start Metro and launch app once
         run: |
-          echo "Attempting to launch app..."
-          xcrun simctl launch --console booted rive.example 2>&1 &
+          cd example
+          yarn start &
+          METRO_PID=$!
           sleep 10
-          echo "Checking if app is running..."
-          xcrun simctl listapps booted | grep -A5 "rive.example" || true
+          echo "Launching app to warm up..."
+          xcrun simctl launch booted rive.example
+          sleep 5
           xcrun simctl terminate booted rive.example || true
+          kill $METRO_PID || true
 
       - name: Run harness tests on iOS
         timeout-minutes: 10