From the article: "This release also introduces Anthropic and Grok backends for Claude and Grok models. (...)

Coming three weeks after Calibre 9.13, the Calibre 9.14 release is here to introduce more AI features, including the ability to generate book covers using AI with different cover styles such as romance, sci-fi, pulp fiction, etc., as well as Anthropic and Grok backends for Claude and Grok models, while removing the GitHub backend."

I don't have it installed at the moment but wonder how easily you can disable that stuff.