Slack notification does not include both agent and customer links

Description

If the user has the “Both internal agent and customer portal links” option selected in JSM links option in global settings and uses Slack as the notification delivery method, only the internal agent link is included in the slack message.

This issue does not occur for direct emails/Jira notifications delivery method.

Additionally, if the “Customer portal link only” option is selected, it is included in the Slack message correctly.