Looking at https://spec.openapis.org/oas/latest.html it still references RFC 7231 when referring to HTTP. But that specification was obsoleted by RFC 9110 in June 2022. I am not confident enough to make the change myself, but if somebody can point me at some "here's how to change the OpenAPI spec" primer, I'd be more than happy to give it a try.