Enforce guest permissions on public projects

Description

I have a project that I want to let anyone view issues and the wiki of, but I don't want to allow users to download the repository, AND I want to be capable of using access tokens in my project to add bug reports to the issue tracker of the project by creating a user that is a guest user of the project and then creating a private access token to the guest user, so that the guest users private access token is used in my project to create issues and I can have my project be public so that anyone can view the public issues and the wiki without being able to download the actual repository.

Proposal

Change it so that public projects enforce Guest user permissions so that they are unable to download the project.

Links / references

(A related issue with the same problem but a different solution)[https://gitlab.com/gitlab-org/gitlab-ce/issues/27029]