update node version in action

Author: prafull-opensignlabs

.github/workflows/deployghpages.yml

@@ -18,7 +18,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-node@v3
         with:
-          node-version: 18
+          node-version: 20
           cache: npm
       - name: Install dependencies
         working-directory: ./docs