upgrade artifact version

refer: https://github.blog/changelog/2024-04-16-deprecation-notice-v3-of-the-artifact-actions/

Author: jasonandjay

.github/workflows/main_ci.yml

@@ -129,7 +129,7 @@ jobs:
       - run: npm ci
       - run: npm run doc
       - name: Upload artifact
-        uses: actions/upload-pages-artifact@v2
+        uses: actions/upload-pages-artifact@v4
         with:
           path: ./docs