Update deploy_book.yml

Author: floriantornow

.github/workflows/deploy_book.yml

@@ -32,6 +32,7 @@ jobs:
         pip install -r doc-requirements.txt
     # Build the book
     - name: Build the book
+      uses: jupyter-book/jupyter-book@v1
       run: |
         jupyter-book build .
     # Deploy the book's HTML to gh-pages branch