Update peaceiris/actions-gh-pages action to v4

Author: renovate[bot]

.github/workflows/gh-pages.yml

@@ -43,7 +43,7 @@ jobs:
         run: hugo --minify
 
       - name: Deploy
-        uses: peaceiris/actions-gh-pages@373f7f263a76c20808c831209c920827a82a2847 # v3
+        uses: peaceiris/actions-gh-pages@4f9cc6602d3f66b9c108549d475ec49e8ef4d45e # v4
         if: ${{ github.ref == 'refs/heads/main' }}
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}