Users can add additional approvers

Problem

We have around 250 projects and a group of 5 senior staff that are set as Approvers on all projects.

We want to ensure that all MRs that are accepted into any project must first be approved by these seniors.

Today a developer can add additional approvers to their MR, which renders this checkpoint in the process moot.

Solution

Remove the ability for a Developer to edit the Approval settings.