Use the latest verison of mBook to fix copy to clipboard

Before this copy code to clipboard on pages with playground (tutorial-5.md) was copying the hidden lines

Author: mart-e

.github/workflows/deploy-book.yml

@@ -15,7 +15,7 @@ jobs:
 
       - name: Test book
         run: |
-          curl -L https://github.com/rust-lang/mdBook/releases/download/v0.4.5/mdbook-v0.4.5-x86_64-unknown-linux-gnu.tar.gz | tar xz
+          curl -L https://github.com/rust-lang/mdBook/releases/download/v0.4.34/mdbook-v0.4.34-x86_64-unknown-linux-gnu.tar.gz | tar xz
           ./mdbook build book
           ./mdbook test book