ci: use consistent node version

Author: MathiasVDA

.github/workflows/deploy-demo.yml

@@ -28,7 +28,7 @@ jobs:
       - name: Setup Node.js
         uses: actions/setup-node@v4
         with:
-          node-version: '20'
+          node-version: '18'
           cache: 'npm'
 
       - name: Install dependencies