docs: do not ask for an unused GitLab token scope

[alessio-locatelli]

I verified by using my personal read_api token and running all-repos-clone -j 1.

[asottile]

did you clone any private repos?

[alessio-locatelli]

did you clone any private repos?

Yes, I did. I only have private repositories on GitLab.

---

Click to expand

By the way, according to https://docs.gitlab.com/ee/user/profile/personal_access_tokens.html, the read_repository scope could only be required for git-over-HTTP (not using the API), which should not be the use case for all-repos, unless I missed something in the source.