Bump actions/cache from 3.3.2 to 4.0.0

Bumps [actions/cache](https://github.com/actions/cache) from 3.3.2 to 4.0.0.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](actions/cache@v3.3.2...v4.0.0)

---
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/ci.yml

@@ -117,7 +117,7 @@ jobs:
 
       - name: Check whether the Guix cache needs updating
         id: check_cache
-        uses: actions/cache/restore@v3.3.2
+        uses: actions/cache/restore@v4.0.0
         with:
           path: ${{ env.guix_cached_paths }}
           key: ${{ steps.cache_name.outputs.ok }}
@@ -134,7 +134,7 @@ jobs:
       - name: Restore the Guix store from cache
         id: restore_cache
         if: ${{ !steps.check_cache.outputs.cache-hit }}
-        uses: actions/cache/restore@v3.3.2
+        uses: actions/cache/restore@v4.0.0
         with:
           path: ${{ env.guix_cached_paths }}
           key: ${{ steps.cache_name.outputs.ok }}
@@ -254,7 +254,7 @@ jobs:
           always() && !cancelled()
           && !steps.check_cache.outputs.cache-hit
           && (steps.guix_shutdown.outcome == 'success')
-        uses: actions/cache/save@v3.3.2
+        uses: actions/cache/save@v4.0.0
         with:
           path: ${{ env.guix_cached_paths }}
           key: ${{ steps.saved_cache_name.outputs.name }}
@@ -279,7 +279,7 @@ jobs:
 
       - name: Restore the Guix store from cache
         id: restore_cache
-        uses: actions/cache/restore@v3.3.2
+        uses: actions/cache/restore@v4.0.0
         with:
           path: ${{ env.guix_cached_paths }}
           key: ${{ needs.build.outputs.cache_name }}