ci: bump actions/cache from 2.1.5 to 3.3.1

Bumps [actions/cache](https://github.com/actions/cache) from 2.1.5 to 3.3.1.
- [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/v2.1.5...v3.3.1)

---
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/build_examples_platformio.yaml

@@ -65,7 +65,7 @@ jobs:
           pip install --upgrade platformio
 
       - name: Restore or Cache Platforms and Libraries
-        uses: actions/cache@v2.1.5
+        uses: actions/cache@v3.3.1
         id: cache_pio
         with:
           path: ~/.platformio