Anthropic PBC on Thursday unveiled a deal with Alphabet Inc.’s Google to supply the artificial intelligence startup with more than a gigawatt of additional computing power, valued in the tens of billions of dollars. The agreement gives Anthropic access to as many as 1 million of Google’s tensor processing units, or TPUs — the company’s chips that are custom designed to accelerate machine learning workloads — and expands its use of the internet giant’s cloud services.