build(deps): bump actions/cache from 3 to 4

Bumps [actions/cache](https://github.com/actions/cache) from 3 to 4.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](actions/cache@v3...v4)

.github/workflows/stack.yml

@@ -45,13 +45,13 @@ jobs:
           date +date=1-%Y-%m >> $GITHUB_OUTPUT
 
       - name: Cache Haskell package metadata
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.stack/pantry
           key: stack-pantry-${{ runner.os }}-${{ steps.cache-date.outputs.date }}
 
       - name: Cache Haskell dependencies
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: |
             ~/.stack/*