[CI] 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)

---
updated-dependencies:
- dependency-name: actions/cache
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/documentation.yml

@@ -55,7 +55,7 @@ jobs:
       # The last step generates dist-newstyle/cache/plan.json for the cache key.
 
     - name: Cache cabal store
-      uses: actions/cache@v3
+      uses: actions/cache@v4
       env:
         cache-name: ${{ runner.os }}-${{ env.ghc }}-documentation-cabal-store
       with: