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] <support@github.com>

.github/workflows/haskell-ci.yml

@@ -240,7 +240,7 @@ jobs:
           $CABAL v2-build $ARG_COMPILER $ARG_TESTS $ARG_BENCH --dry-run all
           cabal-plan
       - name: restore cache
-        uses: actions/cache/restore@v3
+        uses: actions/cache/restore@v4
         with:
           key: ${{ runner.os }}-${{ matrix.compiler }}-${{ github.sha }}
           path: ~/.cabal/store
@@ -278,7 +278,7 @@ jobs:
           rm -f cabal.project.local
           $CABAL v2-build $ARG_COMPILER --disable-tests --disable-benchmarks all
       - name: save cache
-        uses: actions/cache/save@v3
+        uses: actions/cache/save@v4
         if: always()
         with:
           key: ${{ runner.os }}-${{ matrix.compiler }}-${{ github.sha }}

.github/workflows/stack.yml

@@ -79,7 +79,7 @@ jobs:
         # From now on, use env.{GHC|CABAL}_VER rather than matrix.{ghc|cabal}-ver!
 
       - name: Cache dependencies
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         env:
           key: ${{ runner.os }}-stack-${{ env.STACK_VER }}-ghc-${{ env.GHC_VER }}
           ## Just stack.yaml is actually not correct, better would be stack.yaml.lock,