Add Ollama to the optional integration test pipeline on PR checks to run the agentic use cases

[ricardozanini]

What would you like to be added:
Our *IT tests are not running on PR checks since it may slow down or cycle due to the time needed to setup and run Ollama on a small container such as GHA.

This PR is already setup, it can run on demand by the maintainers by commenting on the PR run /integration-tests

Why is this needed:
Improve the overall code reliability.