build(deps): bump actions/cache from 4 to 5

Bumps [actions/cache](https://github.com/actions/cache) from 4 to 5.
- [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...v5)

---
updated-dependencies:
- dependency-name: actions/cache
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/workflows/ports_esp32.yml

@@ -41,7 +41,7 @@ jobs:
 
     - name: Cached ESP-IDF install
       id: cache_esp_idf
-      uses: actions/cache@v4
+      uses: actions/cache@v5
       with:
         path: |
           ./esp-idf/

.github/workflows/ports_zephyr.yml

@@ -43,7 +43,7 @@ jobs:
       run: source tools/ci.sh && echo "ZEPHYR=$ZEPHYR_VERSION" | tee "$GITHUB_OUTPUT"
     - name: Cached Zephyr Workspace
       id: cache_workspace
-      uses: actions/cache@v4
+      uses: actions/cache@v5
       with:
         # note that the Zephyr CI docker image is 15GB. At time of writing
         # GitHub caches are limited to 10GB total for a project. So we only