Add support for GPT-4o

[vishnuravi]

Problem

We would like to add support for the new GPT-4o model from OpenAI to SpeziLLM.

Solution

Since SpeziLLM depends on the OpenAI package to interact with OpenAI services, we will need to first update this package to support GPT-4o. A pull request has been created for this: https://github.com/StanfordBDHG/OpenAI/pull/3

Additional context

No response

Code of Conduct

• [X] I agree to follow this project's Code of Conduct and Contributing Guidelines