fix(ci): add yarn resolution to deduplicate react-native-macos

The set-react-version script updates packages/app/package.json but not
packages/example-macos/package.json, causing two copies of
react-native-macos (0.81.5 from npm + tarball). Add a root-level yarn
resolution to force all workspaces to use the local tarball.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: Saadnajmi

.github/workflows/microsoft-react-native-test-app-integration.yml

@@ -53,6 +53,17 @@ jobs:
         run: |
           node scripts/internal/set-react-version.mts ${{ steps.versions.outputs.react_native_version }} --overrides '{ "react-native-macos": "file:${{ runner.temp }}/react-native-macos.tgz" }'
 
+      - name: Force react-native-macos resolution to local tarball
+        working-directory: react-native-test-app
+        run: |
+          node -e "
+            const fs = require('fs');
+            const pkg = JSON.parse(fs.readFileSync('package.json', 'utf8'));
+            pkg.resolutions = pkg.resolutions || {};
+            pkg.resolutions['react-native-macos'] = 'file:${{ runner.temp }}/react-native-macos.tgz';
+            fs.writeFileSync('package.json', JSON.stringify(pkg, null, 2) + '\n');
+          "
+
       - name: Install dependencies in test app
         working-directory: react-native-test-app
         env: