Introduce .env file for single point of Hugo version

Author: hschwentner

.env

@@ -0,0 +1 @@
+HUGO_VERSION=0.142.0

.github/workflows/hugo.yaml

@@ -31,20 +31,20 @@ jobs:
   # Build job
   build:
     runs-on: ubuntu-latest
-    env:
-      HUGO_VERSION: 0.142.0
     steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          submodules: recursive
+          fetch-depth: 0
+      - name: Load Hugo version
+        run: echo "HUGO_VERSION=$(grep '^HUGO_VERSION=' .env | cut -d'=' -f2)" >> $GITHUB_ENV
       - name: Install Hugo CLI
         run: |
           wget -O ${{ runner.temp }}/hugo.deb https://github.com/gohugoio/hugo/releases/download/v${HUGO_VERSION}/hugo_extended_${HUGO_VERSION}_linux-amd64.deb \
           && sudo dpkg -i ${{ runner.temp }}/hugo.deb          
       - name: Install Dart Sass
         run: sudo snap install dart-sass
-      - name: Checkout
-        uses: actions/checkout@v4
-        with:
-          submodules: recursive
-          fetch-depth: 0
       - name: Setup Pages
         id: pages
         uses: actions/configure-pages@v5