fix(ci): update setuo node to v4 in doc workflow, node-version to 20

Author: tengomucho

.github/workflows/doc-pr-build.yml

@@ -24,9 +24,9 @@ jobs:
 
     steps:
       - uses: actions/checkout@v3
-      - uses: actions/setup-node@v3
+      - uses: actions/setup-node@v4
         with:
-          node-version: '18'
+          node-version: '20'
           cache-dependency-path: "kit/package-lock.json"
 
       - name: Setup environment