Alphabet Inc.’s Waymo plans to launch robotaxi service in Dallas next year in partnership with Avis Budget Group Inc., a push by the autonomous car company to diversify beyond its relationship with Uber Technologies Inc. to further expand across the US.In a first, Waymo said Avis will serve as the fleet partner for its robotaxis in Dallas. Customers can order rides on Waymo’s app while Avis will provide car management services, including infrastructure, vehicle readiness, maintenance and general...