Write rubocop to ban usage of `GitLab.com?` etc in codebase

Problem

We have the ability to use Gitlab.com? (and friends such as Gitlab.dev_env_org_or_com?) as code.

Outside of narrow concerns, this should be discouraged in favor of data-driven approaches. An example of data-driven approach is using application settings

See the epic &7374 (closed)

Proposal

Ban usage of GitLab.com? in codebase. To achieve this, write rubocop to ban Gitlab.com? (and friends) from being called.