[CI] update actions

Author: akru

Diff for: .github/workflows/ci.yml

@@ -20,7 +20,7 @@ jobs:
       - uses: actions/checkout@v2
 
       - name: Setup latest stack
-        uses: actions/setup-haskell@v1
+        uses: haskell/actions/setup@v2
         with:
           enable-stack: true
           stack-version: 'latest'