Add website CI build with artifacts for pull requests

.github/workflows/website.yaml

@@ -5,6 +5,8 @@ on:
   # Runs on pushes targeting the default branch
   push:
     branches: ["gh-pages"]
+  pull_request:
+    types: [opened, reopened, synchronize]
 
   # Allows you to run this workflow manually from the Actions tab
   workflow_dispatch:
@@ -61,12 +63,22 @@ jobs:
           chmod -c -R +rX "_site/" | while read line; do
             echo "::warning title=Invalid file permissions automatically fixed::$line"
           done
+        
+      - name: Upload actions artifact
+        if: github.event_name == 'pull_request'
+        uses: actions/upload-artifact@v4
+        with:
+          name: pull_${{ github.event.pull_request.number }}-website
+          path: _site/
+          overwrite: true
 
-      - name: Upload artifact
+      - name: Upload pages artifact
+        if: github.event_name != 'pull_request'
         uses: actions/upload-pages-artifact@v3
 
   # Deployment job
   deploy:
+    if: github.event_name != 'pull_request'
     environment:
       name: github-pages
       url: ${{ steps.deployment.outputs.page_url }}