Fix package extras for watsonx support

[kiersten-stokes]

#2397 added support for watsonx LLM inference. This PR updates the pyproject.toml to include an ibm_watsonx_ai package extra

NIT: it also removes an unused function, but happy to remove that commit in case there is context that I'm missing here or in the spirit of keeping this PR atomic

[CLAassistant]

All committers have signed the CLA.

[kiersten-stokes]

@Medokins @yoavkatz let me know if you have any thoughts

[kiersten-stokes]

Hmm I see now why this may not have been included - the ibm-watsonx-ai package doesn't support python 3.8. I suppose in that case this is more of an open question to the maintainers about whether there is a precedent for this scenario and what the desired course of action is (if anything)

[baberabb]

Thanks for the PR! the test is failing to the recent transformers update. :)

[ruivieira]

Hi everyone,

I noticed there's no version range for the ibm-watsonx-ai dependency. Is it correct to assume that the minimum safe version would be the latest, at the time of writing (1.1.16)?