Every time computing has fundamentally changed, a new networking company has risen with it. When PCs started connecting to the internet in the 1990s, Cisco and Juniper built the plumbing. When the internet moved into the cloud, Arista and Broadcom took over. Upscale AI is betting AI is that same kind of paradigm shift—and that it’s the company to build the network for this one. The Santa Clara, Calif., startup raised $190 million in a Series A-1…