chore(python-deps): replace ibm_watson_machine_learning with ibm_watsonx_ai (#3302)

# What does this PR do?

This PR updates the Watsonx provider dependencies from
`ibm_watson_machine_learning` to `ibm_watsonx_ai`.

The old package `ibm_watson_machine_learning` is in **deprecation mode**
([[PyPI
link](https://pypi.org/project/ibm-watson-machine-learning/)](https://pypi.org/project/ibm-watson-machine-learning/))
and relies on older versions of dependencies such as `pandas`. Updating
to `ibm_watsonx_ai` ensures compatibility with current dependency
versions and ongoing support.

## Test Plan

I verified the update by running an inference using a model provided by
Watsonx. The model ran successfully, confirming that the new dependency
works as expected.

Co-authored-by: are-ces <[email protected]>

Author: are-ces

llama_stack/providers/registry/inference.py

@@ -292,7 +292,7 @@ def available_providers() -> list[ProviderSpec]:
             api=Api.inference,
             adapter=AdapterSpec(
                 adapter_type="watsonx",
-                pip_packages=["ibm_watson_machine_learning"],
+                pip_packages=["ibm_watsonx_ai"],
                 module="llama_stack.providers.remote.inference.watsonx",
                 config_class="llama_stack.providers.remote.inference.watsonx.WatsonXConfig",
                 provider_data_validator="llama_stack.providers.remote.inference.watsonx.WatsonXProviderDataValidator",

llama_stack/providers/remote/inference/watsonx/watsonx.py

@@ -7,8 +7,8 @@
 from collections.abc import AsyncGenerator, AsyncIterator
 from typing import Any
 
-from ibm_watson_machine_learning.foundation_models import Model
-from ibm_watson_machine_learning.metanames import GenTextParamsMetaNames as GenParams
+from ibm_watsonx_ai.foundation_models import Model
+from ibm_watsonx_ai.metanames import GenTextParamsMetaNames as GenParams
 from openai import AsyncOpenAI
 
 from llama_stack.apis.common.content_types import InterleavedContent, InterleavedContentItem