Small revision in reDoc for trackAndTrace field in Shipments

In the current reDoc specs, the trackAndTrace field under transport is marked as required in the Get a shipment by shipment id response. In practice, this field is omitted when no track and trace data exists (e.g., for letterbox shipments).

On Tuesday, December 2, we’ll update the reDoc documentation to reflect this: trackAndTrace will no longer be marked as required. There are no functional changes; this update solely aligns the documentation with the actual behavior.