Snipe-IT: Incorrect permission for legacy license checkin API

Snipe-IT is an IT asset/license management system. Prior to 8.6.2, the legacy single-seat license checkin flow authorizes the action with the checkout permission instead of the checkin permission, allowing a user who can assign licenses but not unassign them to directly access the old checkin endpoint and reclaim a license seat assigned to another user or asset. This issue is fixed in version 8.6.2.