ci: try newer version of Node.js

Author: agoose77

.github/workflows/deploy.yml

@@ -33,7 +33,7 @@ jobs:
         uses: actions/configure-pages@v3
       - uses: actions/setup-node@v4
         with:
-          node-version: 18.x
+          node-version: 20.x
       - uses: actions/setup-python@v5
         with:
           python-version: '3.12'