feature request: integrate with github caching action

https://github.com/actions/cache

Be nice to speed up the builds using the github cache feature even though its pretty new. **Give us bleeding edge!** 🚩

Specifically *maybe*:

- Use the same [API](https://github.com/actions/cache#inputs)
- Allow runtime dependencies or devcontainer features to be automagically cached (seems like the rebuild every time even on prebuild)
- Support application level dependencies caching automagically via the `setup-*` [packages API](https://docs.github.com/en/actions/using-workflows/caching-dependencies-to-speed-up-workflows)

Thanks!