Geo: Unauthenticated rate limits should not block Geo requests

This seems similar to https://gitlab.com/gitlab-org/gitlab-ce/issues/42910, but this applies to Geo requests. A customer reported:

When you setup Geo, it starts to clone all the repos and after about 6% all of them started to fail due to 429s. If I shut that off, they worked. However, we need to keep that on