OpenAI GPT-5.4: Unable to set reasoning effort = none with temperature = 0

[FeNoMeNa]

Currently, when using OpenAI models such as gpt-5.4 via LangChainGo, it is not possible to configure a request with both:

temperature = 0
reasoning effort = none (via ThinkingModeNone)

According to the OpenAI documentation, this combination should be supported:
https://developers.openai.com/api/docs/guides/latest-model#gpt-54-parameter-compatibility

However, the current implementation appears to reject or ignore this configuration.

[feizhe1996]

I try to add a fix: #1499