update build and deploy workflow based on github example (#15)

.github/workflows/publish.yaml

@@ -10,6 +10,8 @@ on:
 jobs:
   build-and-deploy:
     runs-on: ubuntu-24.04
+    env:
+      JEKYLL_ENV: production
 
     steps:
       - uses: actions/checkout@v4
@@ -18,25 +20,23 @@ jobs:
       - uses: ruby/setup-ruby@v1
         with:
           bundler-cache: true
+      - uses: actions/configure-pages@v5
+        id: pages
       - name: Configure Git
         run: |
           git config user.name "GitHub Actions Bot"
           git config user.email "actions@github.com"
-      - run: bundle exec jekyll build
-      - uses: peaceiris/actions-gh-pages@v3
-        with:
-          github_token: ${{ secrets.GITHUB_TOKEN }}
-          publish_dir: ./_site
+      - run: bundle exec jekyll build --baseurl "${{ steps.pages.outputs.base_path }}"
+      - uses: actions/upload-pages-artifact@v3
+      - uses: actions/deploy-pages@v4
       - run: |
           git add _data/webmention_io_*
           git diff --staged --quiet || git commit -m "publish: ${{ github.sha }}"
           git push origin main
       - run: bundle exec jekyll webmention
-      - run: bundle exec jekyll build
-      - uses: peaceiris/actions-gh-pages@v3
-        with:
-          github_token: ${{ secrets.GITHUB_TOKEN }}
-          publish_dir: ./_site
+      - run: bundle exec jekyll build --baseurl "${{ steps.pages.outputs.base_path }}"
+      - uses: actions/upload-pages-artifact@v3
+      - uses: actions/deploy-pages@v4
       - run: |
           git add _data/webmention_io_*
           git diff --staged --quiet || git commit --amend --no-edit