Update utils.py- Fix error when using AzureOpenAI services

[genlin]

Why are these changes needed?

Seems _kwargs.update(kwargs) will cause errors when using the Azure OpenAI service. It forces the model set in the environment to change to "gpt-4o", which can cause issues (e.g., The API deployment for this resource does not exist.) in Azure.

The model name in Azure can be customized. For example, I created a model based on gpt-4o, and its name is my-gpt-4o that should be used in the API call. If we use gpt-4o as model in the completion API call, the error will occur.

Note I tested the code with the Azure OpenAI service, but I haven't had a chance to run it with OpenAI. Please double-check it.

Related issue number

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• I've included any doc changes needed for https://microsoft.github.io/autogen/. See https://microsoft.github.io/autogen/docs/Contribute#documentation to build and test documentation locally.
• I've added tests (if relevant) corresponding to the changes introduced in this PR.
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[genlin]

#sign-off

[afourney]

I'm traveling today, but will take a look asap. @husseinmozannar is also familiar with this code, if there is urgency

[genlin]

@@husseinmozannar, I found that we have to use "gpt4-o" as the name of the model, unless it will cause unexpected issues when running the codes such as token limit calculation.

File "D:\autogen-main\autogen-main\python\packages\autogen-ext\src\autogen_ext\models\_openai\_model_info.py", line 122, in get_token_limit
   return _MODEL_TOKEN_LIMITS[resolved_model]
          ~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^
KeyError: 'gpt-4o-h1'