Anthropic's terms typically restrict training competing AI models with their outputs, not building standard applications or websites that simply use their API as a tool.
You may not access or use, or help another person to access or use, our Services in the following ways:
2. To develop any products or services that compete with our Services, including to develop or train any artificial intelligence or machine learning algorithms or models or resell the Services.
Let's say you've used Anthropic's model to generate open source software and then some 3rd party trains their model on that. Have you now helped another person to use their service in a way that violates the terms?
I suppose that's pretty far-fetched, though, unless you have some interaction with the party doing the training. Sometimes you might, though: perhaps some company provides services to train a model on exactly your code base, and then provide similar service as Anthropic does for your code base, thus being in direct competition of Antropic as well.