Incorrect URL for Assistants api on Azure

[remixtedi]

Bug Description
According to the API specifications for Azure OpenAI assistants, the current prefix is incorrect. It should not require a deployment ID or ApiPrefix, and we should be able to call the /assistants endpoint directly. You can find the official specifications at https://github.com/Azure/azure-rest-api-specs/blob/main/specification/cognitiveservices/data-plane/AzureOpenAI/inference/preview/2024-05-01-preview/inference.json

When using the Beta Assistants functionality, the API returns a 404 error. After updating the URL on my local fork, the assistants started working.

Additional Context
This issue is specific to the Azure provider and may not be relevant for OpenAI. and I didn't create a PR because I'm not familiar with the structure of the project and it would be simpler and safer if someone else would fix it.

[kayhantolga]

Please feel free to create a PR. I can review and make changes if necessary. I think it would be easier. 🙏

[kayhantolga]

#578 Looks good?

[remixtedi]

#578 Looks good?

It should work! thanks <3