Migrate from denolib/setup-deno to denoland/setup-deno (#387)

Author: uki00a

.github/workflows/testing.yml

@@ -19,7 +19,7 @@ jobs:
         uses: actions/checkout@v2
 
       - name: Setup deno
-        uses: denolib/setup-deno@v2
+        uses: denoland/setup-deno@main
         with:
           deno-version: v1.x