Using the cache action you can now cache your dependencies between workflow runs. This can dramatically reduce the time it takes to run certain steps in your workflow. The rails/rails repository recently started using the cache action in their rubocop workflow reducing the runtime from around seven minutes to roughly one minute.
GitHub Actions now supports self-hosted runners. Hosting your own runners offers maximum flexibility and control of your workflows. Self-host your runners if you need a proprietary image or container, access to on-prem resources, or a more powerful machine. Learn more about using self-hosted runners with your workflows here.