SaaS Free Version NO limitation of namespace seats

Problem to solve

As announced by Upstream, user limits on Free tier of GitLab SaaS will be effective on June 22th.
However, JiHu is still expanding our SaaS users and decided not to follow this Upstream Strategy.

Proposal

We need to find the related Upstream implementation of Upstream, and exclude or deactivate this limitation starting from Milestone 15.1.

At the same time, our marketing team will release a blog of this issue, in order to incent gitlab.com users to try jihulab.com. /cc @louiseluo