Update GitHub Pages workflow file

- Remove the validate job that I added as an example in relation to
  https://discourse.gohugo.io/t/hugo-should-validate-output-formats/55248.
- Use the workflow file from the Hugo docs, verbatim.

Author: jmooring

.github/workflows/hugo.yaml

@@ -18,27 +18,24 @@ jobs:
   build:
     runs-on: ubuntu-latest
     env:
-      DART_SASS_VERSION: 1.97.1
+      DART_SASS_VERSION: 1.97.2
       GO_VERSION: 1.25.5
-      HUGO_VERSION: 0.153.3
+      HUGO_VERSION: 0.154.4
       NODE_VERSION: 24.12.0
       TZ: Europe/Oslo
-    outputs:
-      pages_base_url: ${{ steps.pages.outputs.base_url }}
-      pages_base_path: ${{ steps.pages.outputs.base_path }}
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           submodules: recursive
           fetch-depth: 0
       - name: Setup Go
-        uses: actions/setup-go@v5
+        uses: actions/setup-go@v6
         with:
           go-version: ${{ env.GO_VERSION }}
           cache: false
       - name: Setup Node.js
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@v6
         with:
           node-version: ${{ env.NODE_VERSION }}
       - name: Setup Pages
@@ -55,10 +52,10 @@ jobs:
           echo "${HOME}/.local/dart-sass" >> "${GITHUB_PATH}"
       - name: Install Hugo
         run: |
-          curl -sLJO "https://github.com/gohugoio/hugo/releases/download/v${HUGO_VERSION}/hugo_${HUGO_VERSION}_linux-amd64.tar.gz"
+          curl -sLJO "https://github.com/gohugoio/hugo/releases/download/v${HUGO_VERSION}/hugo_extended_${HUGO_VERSION}_linux-amd64.tar.gz"
           mkdir "${HOME}/.local/hugo"
-          tar -C "${HOME}/.local/hugo" -xf "hugo_${HUGO_VERSION}_linux-amd64.tar.gz"
-          rm "hugo_${HUGO_VERSION}_linux-amd64.tar.gz"
+          tar -C "${HOME}/.local/hugo" -xf "hugo_extended_${HUGO_VERSION}_linux-amd64.tar.gz"
+          rm "hugo_extended_${HUGO_VERSION}_linux-amd64.tar.gz"
           echo "${HOME}/.local/hugo" >> "${GITHUB_PATH}"
       - name: Verify installations
         run: |
@@ -74,7 +71,7 @@ jobs:
           git config core.quotepath false
       - name: Cache restore
         id: cache-restore
-        uses: actions/cache/restore@v4
+        uses: actions/cache/restore@v5
         with:
           path: ${{ runner.temp }}/hugo_cache
           key: hugo-${{ github.run_id }}
@@ -89,71 +86,20 @@ jobs:
             --cacheDir "${{ runner.temp }}/hugo_cache"
       - name: Cache save
         id: cache-save
-        uses: actions/cache/save@v4
+        uses: actions/cache/save@v5
         with:
           path: ${{ runner.temp }}/hugo_cache
           key: ${{ steps.cache-restore.outputs.cache-primary-key }}
-      - name: Upload artifact for deploy job
-        uses: actions/upload-pages-artifact@v3
+      - name: Upload artifact
+        uses: actions/upload-pages-artifact@v4
         with:
           path: ./public
-      - name: Upload artifact for validate job
-        uses: actions/upload-artifact@v4
-        with:
-          name: publish-dir
-          path: ./public
-  validate:
-    runs-on: ubuntu-latest
-    needs: build
-    steps:
-      - name: Set up Ruby
-        uses: ruby/setup-ruby@v1
-        with:
-          ruby-version: 3.3
-          bundler-cache: true
-      - name: Download artifact
-        uses: actions/download-artifact@v4
-        with:
-          name: publish-dir
-          path: ./
-      - name: Validate HTML and CSS
-        uses: anishathalye/proof-html@v2
-        with:
-          directory: ./
-          enforce_https: true
-          ignore_empty_alt: true
-          ignore_url_re: |
-            ^foo$
-          tokens: |
-            {"https://github.com": "${{ secrets.GITHUB_TOKEN }}"}
-          swap_urls: |
-            ${{ format('{{ "^{0}" : "" }}', needs.build.outputs.pages_base_path) }}
-      - name: Install libxml2-utils
-        run: sudo apt update && sudo apt install libxml2-utils
-      - name: Verify that RSS and sitemap are valid XML
-        run: |
-          xmllint --noout ./index.xml
-          xmllint --noout ./sitemap.xml
-      - name: Download RSS schema
-        run: wget https://raw.githubusercontent.com/jthelin/rss2schema/refs/heads/main/schema/rss-2_0.xsd
-      - name: Validate RSS
-        uses: ChristophWurst/xmllint-action@v1
-        with:
-          xml-file: ./index.xml
-          xml-schema-file: ./rss-2_0.xsd
-      - name: Download sitemap schema
-        run: wget https://www.sitemaps.org/schemas/sitemap/0.9/sitemap.xsd
-      - name: Validate sitemap
-        uses: ChristophWurst/xmllint-action@v1
-        with:
-          xml-file: ./sitemap.xml
-          xml-schema-file: ./sitemap.xsd
   deploy:
     environment:
       name: github-pages
       url: ${{ steps.deployment.outputs.page_url }}
     runs-on: ubuntu-latest
-    needs: [build, validate]
+    needs: build
     steps:
       - name: Deploy to GitHub Pages
         id: deployment