As an Administrator, I want the system to send notification emails to all managers upon transitioning a review period to Awaiting Approval so that they are aware they need to review reviewer assignments.

Acceptance Criteria:

• Upon confirmation of reviewer assignments and the transition to Awaiting Approval state, the system triggers emails to all managers.
• The email should notify them review assignments are ready for their approval and provide a link to the review period dashboard where they can review and approve the assignments (See Allow managers to confirm review assignments #2292).