Remove moonshot and qianfan model

[markpollack]

These models have moved to https://github.com/orgs/spring-ai-community/repositories

The links to these models in the reference documentation should point to the new locations.

[ilayaperumalg]

Closing this as complete as the new repos are:

https://github.com/spring-ai-community/qianfan
https://github.com/spring-ai-community/moonshot