Update eleventy.yml

Update version on upload-pages-artifact to v3

Author: sharonmleon

.github/workflows/eleventy.yml

@@ -45,4 +45,4 @@ jobs:
           path: './_site'
       - name: Deploy to GitHub Pages
         id: deployment
-        uses: actions/deploy-pages@v1
+        uses: actions/deploy-pages@v3