GitHub Enterprise Server includes most GitHub-authored actions, and has options for enabling access to other actions from GitHub.com and GitHub Marketplace.
To allow GitHub Actions in your enterprise to use actions from GitHub.com, you can connect your enterprise instance to GitHub Enterprise Cloud.
For users that need access to actions from GitHub.com, you can sync specific actions to your enterprise.
You can update the actions that are bundled with your enterprise, or use actions directly from GitHub.com.
To use the included actions/setup actions on self-hosted runners without internet access, you must first populate the runner's tool cache for your workflows.
actions/setup