Switch to actively maintained haskell/actions/setup for CI

Author: Gaël Deest

.github/workflows/main.yml

@@ -25,7 +25,7 @@ jobs:
     steps:
     - uses: actions/checkout@v2
 
-    - uses: actions/setup-haskell@v1.1.4
+    - uses: haskell/actions/setup@v1
       id: setup-haskell-cabal
       name: Setup Haskell
       with:
@@ -90,7 +90,7 @@ jobs:
     steps:
     - uses: actions/checkout@v2
 
-    - uses: actions/setup-haskell@v1.1.4
+    - uses: haskell/actions/setup@v1
       name: Setup Haskell Stack
       with:
         ghc-version: ${{ matrix.ghc }}