Add Firebase config to Dockerfile and workflow

.github/workflows/docker.yml

@@ -42,4 +42,12 @@ jobs:
         context: .
         push: true
         tags: ${{ steps.meta.outputs.tags }}
-        labels: ${{ steps.meta.outputs.labels }}
+        labels: ${{ steps.meta.outputs.labels }}
+        build-args: |
+          NEXT_PUBLIC_FIREBASE_API_KEY=dummy-api-key
+          NEXT_PUBLIC_FIREBASE_AUTH_DOMAIN=dummy.firebaseapp.com
+          NEXT_PUBLIC_FIREBASE_PROJECT_ID=dummy-project
+          NEXT_PUBLIC_FIREBASE_STORAGE_BUCKET=dummy-project.appspot.com
+          NEXT_PUBLIC_FIREBASE_MESSAGING_SENDER_ID=123456789
+          NEXT_PUBLIC_FIREBASE_APP_ID=1:123456789:web:abcdef123456
+          NEXT_PUBLIC_ENCRYPTION_KEY=dummy-encryption-key