Feat: add gpt 5 models and verbosity param

[apappascs]

Add gpt-5 models and update their tests

[apappascs]

@sobychacko @markpollack updating the latest changes from 1a3ed95

Gpt-5 models: https://platform.openai.com/docs/models
New params: https://cookbook.openai.com/examples/gpt-5/gpt-5_new_params_and_tools
Using Gpt-5: https://platform.openai.com/docs/guides/latest-model

[sobychacko]

Is this not the case anymore? In that case, we need to update the docs changed in this commit: https://github.com/spring-projects/spring-ai/pull/4068/files

[apappascs]

thank youi for pointing out this one @sobychacko . it is the case for all gpt 5 models but not the gpt-5-chat model . https://community.openai.com/t/temperature-in-gpt-5-models/1337133/25
I have update documentation and added tests as well

[sobychacko]

Does it mean that the gpt 5 models default to a value of temperature 1.0? If so, I think we should make that clear in the docs or javadocs. From what I hear from you, the GPT 5 models completely ignore temperature and internally default to a value of 1.0. Is that correct?

[apappascs]

Yes, that is correct. Azure mentions also more params that are not supported, but I am am not sure if that info has to be on spring ai documentation as it is not a limitation of the framework but from the LLM model itself.

The following are currently unsupported with reasoning models:

temperature, top_p, presence_penalty, frequency_penalty, logprobs, top_logprobs, logit_bias, max_tokens

https://learn.microsoft.com/en-us/azure/ai-foundry/openai/how-to/reasoning?tabs=gpt-5%2Cpython-secure%2Cpy#not-supported

[xak2000]

GPT 5 models completely ignore temperature and internally default to a value of 1.0

I just wanted to point out that it is not technically correct. In my experiments when the temperature is set to any value other than 1.0 the OpenAI API actually throws an error. I.e. it does not ignore the temperature parameter, instead it expects/forces it to always be 1.0.

This is important difference because e.g. with the default auto-configuration the temperature is 0.7 (see OpenAiChatProperties). So, if the model is set to gpt-5-* and the temperature is not explicitly set to 1.0, the default 0.7 is used in the API request and the ChatClient throws an exception.

I'm not sure how this problem should be solved on the library level. Automatically set the temperature to 1.0 when model is set to one of well-know model names? Probably this approach would be acceptable on OpenAiChatProperties level, when it creates the options object and sets the default temperature.. It could set it to 1.0 (or skip setting it if it works too) if the model is one of well-known models that does not support custom temperature.