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](https://github.com/actions/cache/compare/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/ci-linux-ros.yml

@@ -30,7 +30,7 @@ jobs:
       # eiquadprog is not yet available in ROS2
       - run: sed -i "/eiquadprog/d" package.xml
       # This step will fetch/store the directory used by ccache before/after the ci run
-      - uses: actions/cache@v3
+      - uses: actions/cache@v4
         with:
           path: ${{ env.CCACHE_DIR }}
           key: ccache-${{ matrix.env.ROS_DISTRO }}-${{ matrix.env.ROS_REPO }}