Bump peaceiris/actions-gh-pages from 3.8.0 to 3.9.0 (#14276)

.github/workflows/docs.yaml

@@ -58,7 +58,7 @@ jobs:
           
       # Deploy to the target directory.
       - name: Deploy to gh pages
-        uses: peaceiris/actions-gh-pages@068dc23d9710f1ba62e86896f84735d869951305 # v3.8.0
+        uses: peaceiris/actions-gh-pages@de7ea6f8efb354206b205ef54722213d99067935 # v3.9.0
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}
           publish_dir: ./book

changelog.d/14276.misc

+Bump peaceiris/actions-gh-pages from 3.8.0 to 3.9.0.