Establish guidelines for handling objections to maintainer readiness

Why is this change being made?

Recently, engineering leadership encountered a scenario where we received both approval and rejection to granting maintainer status to a team member. The criteria for approval and rejection conflict with how to resolve the disagreement. Furthermore, the steps and guidelines do not establish to what discretion an engineering manager has in scenarios where we should balance code quality, maintainer trust, standards, and enabling other engineers.

This MR seeks to add guidelines for objection in order to address questions/gaps in the process such as:

• majority approval
• one disapproval vetoing N number of approvals
• possible situations where a trainee maintainer is repeatedly rejected due to bias or recalcitrant views
• managerial discretion in approval

Author Checklist

• Provided a concise title for this Merge Request (MR)
• Added a description to this MR explaining the reasons for the proposed change, per say why, not just what
  • Copy/paste the Slack conversation to document it for later, or upload screenshots. Verify that no confidential data is added.
• Assign reviewers for this MR to the correct Directly Responsible Individual/s (DRI)
  • If the DRI for the page/s being updated isn’t immediately clear, then assign it to one of the people listed in the Maintained by section on the page being edited
  • If your manager does not have merge rights, please ask someone to merge it AFTER it has been approved by your manager in #mr-buddies
• If the changes affect team members, or warrant an announcement in another way, please consider posting an update in #whats-happening-at-gitlab linking to this MR
  • If this is a change that directly impacts the majority of global team members, it should be a candidate for #company-fyi. Please work with internal communications and check the handbook for examples.

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