chore: remove extra mdbook.yml

Author: jeffabailey

.github/workflows/mdbook.yml

@@ -37,9 +37,6 @@ jobs:
           curl --proto '=https' --tlsv1.2 https://sh.rustup.rs -sSf -y | sh
           rustup update
           cargo install --version ${MDBOOK_VERSION} mdbook
-      - name: Install mdBook preprocessors
-        run: |
-          cargo install mdbook-mermaid mdbook-embedify
       - name: Setup Pages
         id: pages
         uses: actions/configure-pages@v5