Merge pull request #352 from ruby/dependabot/github_actions/actions/deploy-pages-4

Author: kateinoigakukun

.github/workflows/docs.yml

@@ -45,5 +45,5 @@ jobs:
     steps:
       - name: Deploy to GitHub Pages
         id: deployment
-        uses: actions/deploy-pages@v2
+        uses: actions/deploy-pages@v4