(Reuters) -Britain’s Arrival SA said it was laying off 50% of its employees in a move that will help halve its cash operating expenses, as the electric-vehicle startup tries to ride out a cash crunch threatening its survival in the competitive market. The move announced on Monday underscores the pressure on EV startups that had promised to disrupt the automotive industry but are now scrambling to slash costs in the face of supply chain issues and steep raw material prices. High demand for electric vans has brought legacy players including General Motors’ BrightDrop, Ford Motor Co and upstarts …