Update assignee for CEO Shadow applications to remove the CEO from the approval

Why is this change being made?

The approval requests to participate in the CEO Shadow program currently instructs applicants to assign the MR to the CEO and mention the CEO in Slack. This MR removes that instruction and replaces it with assigning the MR to the Executive Business Admin supporting the CEO, and to mention the Executive Business Admin supporting the CEO in the ceo-shadow channel in Slack.

This is to reduce noise in SLack for the CEO

Does this MR meet the acceptance criteria?

Assign to DRI

• Did you assign this change to the correct DRI of the page or information you are changing?

Conformity

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