Install extra ghc with setup action

Author: andreasabel

.github/workflows/validate.yml

@@ -234,8 +234,15 @@ jobs:
       #     sudo chown -R $USER /usr/local/.ghcup
       #     sudo chmod -R 777 /usr/local/.ghcup
 
-      - name: Install extra compiler
-        run: ghcup install ghc ${{ matrix.extra-ghc }}
+      # - name: Install extra compiler
+      #   run: ghcup install ghc ${{ matrix.extra-ghc }}
+
+      - uses: haskell-actions/setup@v2
+        id: setup-haskell
+        with:
+          ghc-version: ${{ matrix.extra-ghc }}
+          cabal-version: latest
+          cabal-update: false
 
       - uses: haskell-actions/setup@v2
         id: setup-haskell