fix(ci): install mdbook-linkcheck in CI

Signed-off-by: Victor Adossi <vadossi@cosmonic.com>

Author: vados-cosmonic

.github/workflows/mdbook.yml

@@ -30,7 +30,8 @@ jobs:
     runs-on: ubuntu-latest
     env:
       MDBOOK_VERSION: 0.4.21
-      ALERTS_VERSION: 0.6.7
+      MDBOOK_ALERTS_VERSION: 0.6.7
+      MDBOOK_LINKCHECK_VERSION: 0.7.7
       PUBLISH_DOMAIN: component-model.bytecodealliance.org
     steps:
       - uses: actions/checkout@v3
@@ -39,7 +40,8 @@ jobs:
           curl --proto '=https' --tlsv1.2 https://sh.rustup.rs -sSf -y | sh
           rustup update
           cargo install --version ${MDBOOK_VERSION} mdbook
-          cargo install --version ${ALERTS_VERSION} mdbook-alerts
+          cargo install --version ${MDBOOK_ALERTS_VERSION} mdbook-alerts
+          cargo install --version ${MDBOOK_LINKCHECK_VERSION} mdbook-linkcheck
       - name: Setup Pages
         id: pages
         uses: actions/configure-pages@v3