Revert "ci: Don't need to run mdbook-linkcheck again during deploy"

This reverts commit 5de26d9.

Author: sourcefrog

.github/workflows/book.yml

@@ -60,6 +60,9 @@ jobs:
         uses: taiki-e/install-action@v2
         with:
           tool: mdbook
+      - name: Install mdbook-linkcheck
+        # Temporarily pull the fix for https://github.com/Michael-F-Bryan/mdbook-linkcheck/pull/98
+        run: cargo install mdbook-linkcheck --git https://github.com/schilkp/mdbook-linkcheck --branch mdbook_v0.5
       - name: Setup Pages
         uses: actions/configure-pages@v5
       - name: Build book