Update build_deploy.yaml

Author: yallup

.github/workflows/build_deploy.yaml

@@ -50,7 +50,7 @@ jobs:
 
     # Upload the book's HTML as an artifact
     - name: Upload artifact
-      uses: actions/upload-pages-artifact@v2
+      uses: actions/upload-pages-artifact@v4
       with:
         path: "_build/html"