Rename "Push Rules" in Admin Area

Problem to solve

In #39060 (closed) we added new settings to the Push Rules page in the Admin Area of GitLab. The addition of these settings - project-level settings brought to the instance level to provide greater control of MR approvals - breaks the paradigm of "push rules" and necessitates a new name for this view. Since the settings are no longer exclusively related to push rules, we'll need a more apt name.

Proposal

Update the navigation item in the Admin Area