Remove Growth Section KPIs from Eng since they are under Product

Why is this change being made?

The Growth Team's KPIs are the top 4 product KPIs. https://about.gitlab.com/handbook/business-ops/data-team/kpi-index/#product-kpis

Having this was confusing in a previous key meeting.

Does this MR meet the acceptance criteria?

Conformity

• Added description to this MR explaining the reasons for the proposed change, per say-why-not-just-what