Bump haskell-actions/setup from 2.7 to 2.8 (#2654)

Bumps [haskell-actions/setup](https://github.com/haskell-actions/setup) from 2.7 to 2.8.
- [Release notes](https://github.com/haskell-actions/setup/releases)
- [Commits](haskell-actions/setup@v2.7...v2.8)

---
updated-dependencies:
- dependency-name: haskell-actions/setup
  dependency-version: '2.8'
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/main.yml

@@ -50,7 +50,7 @@ jobs:
           submodules: true
       - id: setup-haskell-cabal
         name: "Setup Haskell environment"
-        uses: haskell-actions/setup@v2.7
+        uses: haskell-actions/setup@v2.8
         with:
           enable-stack: true
           stack-version: "latest"