Update build.yml

oh god

Author: markjfannon

.github/workflows/build.yml

@@ -41,7 +41,7 @@ jobs:
         uses: actions/configure-pages@v2
 
       - name: Upload artifact
-        uses: actions/upload-pages-artifact@v2
+        uses: actions/upload-pages-artifact@v4
         with:
           path: 'pages'