Repository administrators can turn off project boards for a repository if you or your team manages work differently.
When you disable project boards, you will no longer see project board information in timelines or audit logs.
On GitHub, navigate to the main page of the repository.
Under your repository name, click Settings.
Under "Features," unselect the Projects checkbox.
After project boards are disabled, existing project boards are inaccessible at their previous URLs. If you decide to re-enable project boards, any project boards that were previously added will be available.