Bump actions/cache from 4 to 6

Bumps [actions/cache](https://github.com/actions/cache) from 4 to 6.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](https://github.com/actions/cache/compare/v4...v6)

---
updated-dependencies:
- dependency-name: actions/cache
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/emulated.yml

@@ -53,7 +53,7 @@ jobs:
 
       - name: restore ccache
         # setup the GitHub cache used to maintain the ccache from one job to the next
-        uses: actions/cache/restore@v4
+        uses: actions/cache/restore@v6
         with:
           # location of the ccache of the chroot in the root file system
           path: /home/runner/rootfs/alpine-latest-${{ matrix.arch }}/home/runner/.ccache
@@ -102,7 +102,7 @@ jobs:
       - name: save ccache
         # Save the cache after we are done (successfully) building
         # This helps to retain the ccache even if the subsequent steps are failing.
-        uses: actions/cache/save@v4
+        uses: actions/cache/save@v6
         with:
           path: /home/runner/rootfs/alpine-latest-${{ matrix.arch }}/home/runner/.ccache
           key: ${{ steps.ccache-prepare.outputs.key }}