fix(duplicate): projectManager not populated in projectPayloadData on duplicate project page

[sujalkalauni]

Bug Description

In src/app/[locale]/projects/duplicate/[id]/components/DuplicateProject.tsx,
the projectManager field is correctly fetched and stored in local state,
but it was never assigned in projectPayloadData — the object sent to the API.

projectOwner and leadArchitect were both assigned but projectManager
was missing entirely.

Impact

When duplicating a project, the Project Manager is silently dropped —
the duplicated project always has an empty Project Manager field regardless
of what the source project had.

Fix

Add the missing line to projectPayloadData:

projectManager: project._embedded?.projectManager?.email ?? '',