feat: Resolving UserWarning about llama-index-llms-dashscope (#16965)

* feat: Resolving UserWarning about llama-index-llms-dashscope

In Pydantic V2, protected_namespaces is a configuration option used to prevent certain namespace keywords
          (such as model_, etc.) from being used as field names. so we need to disable it here.

* Update pyproject.toml

update version to 0.2.6

* lint

---------

Co-authored-by: Andrei Fajardo <andrei@nerdai.io>