chore: preinstall Deno and not rely on CLI to do that

Author: pieh

.github/workflows/test.yml

@@ -36,5 +36,9 @@ jobs:
       - name: Linting
         run: npm run format:ci
         if: "${{ matrix.node-version == '20.19.1' }}"
+      - name: Install Deno
+        uses: denoland/setup-deno@v1
+        with:
+          deno-version: 2.5.6
       - name: Run tests
         run: npm run test