Allow the use of restricted access and still have the ability to share projects with other groups

Proposal

In a recent GitLab premium customer ticket it was found that enabling restricted access for seat control actually forces the "Prevent a project from being shared with groups" setting to be enabled.

The docs will be updated appropriately as this isn't currently clear that this behavior exists. The behavior in the code that is responsible for this can be found here: https://gitlab.com/gitlab-org/gitlab/-/blob/master/ee/app/models/ee/namespace_setting.rb under the method name block_seat_overages.

The customer relies of the ability to share projects with other groups and would like to be able to utilize both features at the same time.