add deepseek chat model support

[walle1027]

Please do a quick search on GitHub issues first, the feature you are about to request might have already been requested.

Expected Behavior
org.springframework.ai.chat.messages.Message add reasoning_content

[apappascs]

Thank you for opening this issue, @walle1027.

There is already a PR open to resolve this: #2192.

Additionally, there is another issue #2283 with the same expectation.

[johnsonr]

You can also use Deepseek models via Ollama.

[markpollack]

I am closing this as there are several other issues on the same topic. Search for remaining deepseek issues and there are some comments on how we will proceed to handle supporting deepseek.