ci: Install GHC/stack via haskell-actions/setup consistently

This action makes sure to always have the correct GHC and/or stack
version installed in all environments. This solves problem where ghc or
stack might not be available on newer macos images anymore or where
ghcup is not available by default on our new custom github runner on
arm.

.github/workflows/build.yaml

@@ -119,6 +119,12 @@ jobs:
     runs-on: ${{ matrix.runs-on }}
     steps:
       - uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29 # v4.1.6
+      - uses: haskell-actions/setup@64aa5146ed5bd91f181552b8b5fbe50fbd2bd3fe # v2.7.1
+        with:
+          ghc-version: 9.4.5
+          enable-stack: true
+          stack-no-global: true
+          stack-setup-ghc: true
       - name: Cache ~/.stack
         uses: ./.github/actions/cache-on-main
         with:
@@ -172,15 +178,9 @@ jobs:
     runs-on: ubuntu-22.04
     steps:
       - uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29 # v4.1.6
-      - name: ghcup
-        run: |
-          # GHC 9.8.2 is not available in regular release channel, yet.
-          ghcup config add-release-channel https://raw.githubusercontent.com/haskell/ghcup-metadata/master/ghcup-vanilla-0.0.8.yaml
-          ghcup install ghc ${{ matrix.ghc }}
-          ghcup set ghc ${{ matrix.ghc }}
-      - name: Fix caching
-        run: |
-          mkdir ~/.cabal
+      - uses: haskell-actions/setup@64aa5146ed5bd91f181552b8b5fbe50fbd2bd3fe # v2.7.1
+        with:
+          ghc-version: ${{ matrix.ghc }}
       - name: Cache .cabal
         uses: ./.github/actions/cache-on-main
         with:
@@ -197,8 +197,6 @@ jobs:
           prefix: cabal-${{ matrix.ghc }}-dist-newstyle-${{ hashFiles('postgrest.cabal', 'cabal.project', 'cabal.project.freeze') }}
           suffix: ${{ hashFiles('**/*.hs') }}
       - name: Install dependencies
-        run: |
-          cabal update
-          cabal build --only-dependencies --enable-tests --enable-benchmarks
+        run: cabal build --only-dependencies --enable-tests --enable-benchmarks
       - name: Build
         run: cabal build --enable-tests --enable-benchmarks all