Fix setup for agentic_rl_text2sql notebook

[iuliaturc]

Human-written PR description 🙃

These changes make the notebook runnable in one go:

1. [critical] update the pip install list
2. add git clone and cd bash commands so that you can just open the notebook in e.g. Colab without moving any other files manually
3. download the BIRD dataset automatically (it takes a while to figure out the official source and where to place the files)

Note to reviewer: Github's UI makes .ipynb diff hard to read. Here's a more readable diff (made with nbdime):

[Hecate0821]

Thanks @iuliaturc — this is a great fix, and the nbdime screenshot made it easy to review. 🙌

A note on process: this repository's main is a generated mirror — it only accepts the automated promotion PR from our internal monorepo, which is why the Promotion source gate check fails on external PRs. Direct merges here would be overwritten by the next promotion.

So we've ported your changes into internal staging (with you credited via Co-authored-by), including one small adjustment on top: the setup cell now skips the git clone when the notebook already runs inside a local checkout (a re-run would otherwise fail on the existing cookbook/ directory).

Once the internal PR merges, the promotion automation will publish your changes to this repo's main automatically. We'll close this PR once that lands — your contribution will ship, just through the generated path.

[iuliaturc]

Awesome, thanks for the detailed explanation of the process!