About GitHub Actions permissions for your organization
By default, after GitHub Actions is enabled on your enterprise, it is enabled on all repositories and organizations. You can choose to disable GitHub Actions or limit them to private actions only, which means that people can only use actions that exist in your repository. For more information about GitHub Actions, see "About GitHub Actions."
You can enable GitHub Actions for all repositories in your organization. When you enable GitHub Actions, workflows are able to run actions located within your repository and any other public repository. You can disable GitHub Actions for all repositories in your organization. When you disable GitHub Actions, no workflows run in your repository.
Alternatively, you can enable GitHub Actions for all repositories in your organization but limit the actions a workflow can run. When you enable local actions only, workflows can only run actions located in your repository, organization, or enterprise.