Bump haskell-actions/setup from 2.7.3 to 2.7.6

Bumps [haskell-actions/setup](https://github.com/haskell-actions/setup) from 2.7.3 to 2.7.6.
- [Release notes](https://github.com/haskell-actions/setup/releases)
- [Commits](haskell-actions/setup@v2.7.3...v2.7.6)

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

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/build.yml

@@ -17,7 +17,7 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-${{ matrix.ghc }}-
 
-      - uses: haskell-actions/[email protected].3
+      - uses: haskell-actions/[email protected].6
         with:
           ghc-version: '8.10.7'
           enable-stack: true