Allow fullstack roles in Dev sub-department

Why is this change being made?

The re-organization in FY24-Q1 resulted in redeployment of at least one Fullstack Engineer from Incubation to a Dev team (Plan). The handbook guidance currently prohibits Fullstack roles outside of Growth, Fulfillment, and Secure. This change updates the guidance to allow for this role within Dev.

Author Checklist

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