fix: update github pages artifacts v2->v3 (#561)

Author: mbifulco

.github/workflows/jekyll.yml

@@ -49,7 +49,7 @@ jobs:
           JEKYLL_ENV: production
       - name: Upload artifact
         # Automatically uploads an artifact from the './_site' directory by default
-        uses: actions/upload-pages-artifact@v2
+        uses: actions/upload-pages-artifact@v3
 
   # Deployment job
   deploy: