Update helplab process

Change the instructions for the Manager tasks for the group change assignment in Workday.

It is no longer necessary to email people-connect. Instead, log a HelpLab ticket.

• https://handbook.gitlab.com/handbook/business-technology/enterprise-applications/guides/helplab-guide/
• Slack: https://gitlab.slack.com/archives/C02E7JGBU4E/p1713991344837339