add: deploy to firebase hosting

.github/workflows/firebase-hosting-pull-request.yml

@@ -0,0 +1,21 @@
+# This file was auto-generated by the Firebase CLI
+# https://github.com/firebase/firebase-tools
+
+name: Deploy to Firebase Hosting on PR
+on: pull_request
+permissions:
+  checks: write
+  contents: read
+  pull-requests: write
+jobs:
+  build_and_preview:
+    if: ${{ github.event.pull_request.head.repo.full_name == github.repository }}
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - run: npm run build
+      - uses: FirebaseExtended/action-hosting-deploy@v0
+        with:
+          repoToken: ${{ secrets.GITHUB_TOKEN }}
+          firebaseServiceAccount: ${{ secrets.FIREBASE_SERVICE_ACCOUNT_VIRTUAL_NATSUMATSURI }}
+          projectId: virtual-natsumatsuri