By default, all public repositories are included in the GitHub Archive Program, a partnership between GitHub and organizations such as Software Heritage Foundation and Internet Archive to ensure the long-term preservation of the world's open source software. For more information, see "About archiving content and data on GitHub."
If you opt out of the GitHub Archive Program for a repository, the repository will be excluded from any long-term archives that GitHub may create in the future.
On GitHub.com, navigate to the main page of the repository.
Under your repository name, click Settings. If you cannot see the "Settings" tab, select the dropdown menu, then click Settings.
Under "Features", select or deselect Preserve this repository.