chore(deps): update dependency deno to v2 (#37)

Author: MikuroXina

.github/workflows/ci.yaml

@@ -21,7 +21,7 @@ jobs:
       - name: Setup deno
         uses: denoland/setup-deno@v1
         with:
-          deno-version: v1.x
+          deno-version: 2.x
 
       - name: Install mdbook
         uses: peaceiris/actions-mdbook@v2