Update Firebase workflow to use node@18

Author: daohoangson

.github/workflows/firebase_functions.yml

@@ -1,9 +1,9 @@
 name: Cloud Functions for Firebase
 on:
   push:
-    paths: 
+    paths:
       - .github/workflows/firebase_functions.yml
-      - 'firebase/functions/**'
+      - "firebase/functions/**"
 
 jobs:
   deploy:
@@ -16,7 +16,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v4
         with:
-          node-version: 16.x
+          node-version: 18.x
       - uses: actions/cache@v4
         with:
           path: ~/.npm