Maybe CFAA, but then again IIRC scraping was ruled legal.
Of course, in the spirit of adversarial interoperability, this is a path to freedom. It's unfortunate that user-agent discrimination even became a thing.
I doubt there is any legal issues with it, but Cloudflare probably reserves the right to completely block your IP forever if they catch you doing it (by for example updating Turnstile to fingerprint this publicly accessible solver library)
Maybe in some country like US there might be, bet the rest of the world? None