Update rollout process for commissions

Why is this change being made?

Historically, GitLab has attempted to focus on target dates for the comp plan rollout which has been difficult to hit given the nature of a process that requires a lot of approvals and has a rollout plan for multiple different types of roles. This MR aims to help identify the rollout workflow in a way that helps teams better understand the current state of the process.

Author Checklist

• Provided a concise title for the MR
• Added a description to this MR explaining the reasons for the proposed change, per say-why-not-just-what
• Assign this change to the correct DRI
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