Speed up CI

.github/workflows/GitHub pages.yml

@@ -35,16 +35,15 @@ jobs:
 
       - name: Install mdBook
         run: |
-          curl --proto '=https' --tlsv1.2 https://sh.rustup.rs -sSf -y | sh
-          rustup update
-          cargo install --version ${MDBOOK_VERSION} mdbook
+          mkdir bin
+          curl -sSL https://github.com/rust-lang/mdBook/releases/download/v0.4.40/mdbook-v0.4.40-x86_64-unknown-linux-gnu.tar.gz | tar -xz --directory=bin
       
       - name: Setup Pages
         id: pages
         uses: actions/configure-pages@v5
-        
+
       - name: Build with mdBook
-        run: mdbook build
+        run: bin/mdbook build
 
       - name: Upload artifact
         uses: actions/upload-pages-artifact@v3
@@ -56,6 +55,7 @@ jobs:
     environment:
       name: github-pages
       url: ${{ steps.deployment.outputs.page_url }}
+
     runs-on: ubuntu-latest
     needs: build
     steps: