Yes, it is possible to hide projects on GitHub. There are a few ways to do this:
Make the repository private: You can make a repository private so that only people you invite can see and access the repository. You can do this by going to the repository settings and selecting “Make private”
Archive the repository: You can archive a repository to stop further development on it. This will hide it from the “Active” repositories list on your profile, but it will still be accessible to anyone who has the link. You can archive a repository by going to the repository settings and selecting “Archive this repository”
Delete the repository: You can delete a repository permanently. This will remove it from your profile and it will not be accessible to anyone. Deletion is permanent, so be sure you really want to delete the repository before you proceed. You can delete a repository by going to the repository settings and selecting “Delete this repository”.
It’s important to note that once you make a repository private, archive it or delete it, it will not be visible by other people and it will not be searchable on GitHub. However, the repository’s data, commits, and forks will be stored in GitHub’s database and it will be accessible to GitHub’s administrator or the person who has access to the repository.