Migrating OpenAIBackend to openai>=1 (#1707)

[peguerosdc]

This PR changes OpenAIBackend to work with openai>=1 by following OpenAI's migration guide where:

• openai.Embedding.create() -> client.embeddings.create()

Note that the example in the docs was already correct:

client = openai.OpenAI(api_key="sk-...")
openai_embedder = OpenAIBackend(client, "text-embedding-ada-002")

Fixes #1707

[peguerosdc]

Also, I think it would be good to specify the OpenAI version supported by BERTopic in the setup.py like:

openai_packages = [
    "openai>=1,<2"
]

setup(
    extras_require={
        "openai": openai_packages
    }
)

But I didn't do it because I don't know if it would break anything for someone else.

[MaartenGr]

Thanks for the PR! One small thing. Could you set the version back to 0.16.0? I am not yet creating an official release for 0.16.1.

[peguerosdc]

Done, thanks for the review!

[MaartenGr]

Awesome, thanks for your work on this PR!