GOTHENBURG :European truckmaking rivals AB Volvo and Daimler Truck hope to cut costs and reduce reliance on suppliers by jointly developing a software-defined vehicle program, they said on Tuesday. Fleets and truck manufacturers, like automakers, have been racing to produce technology-packed vehicles while also grappling with the need to reduce costs. Truckmakers are currently heavily reliant on suppliers because their software is closely tied to hardware, but Daimler and Volvo's new business -