update the RAGAS cookbook to work with `ragas-haystack>=4.0.0`

[sjrl]

Once this PR is merged deepset-ai/haystack-core-integrations#3207 we should update the cookbook to reflect the breaking changes that were needed to support the latest version of RAGAS.

Look at the linked PR for more details on how the component changed.

[A-Amini]

Hi @bilgeyucel and @sjrl

I'd love to take this on and update the cookbook to reflect the breaking changes from the Ragas >=0.4.3 integration updates (PR #3207).
Since the docs PR (#11178) was just mentioned, I'll review those updates and the core integration changes to ensure the cookbook matches the new component structure perfectly.

Could you please assign this issue to me? Thanks!

[sjrl]

Hey @A-Amini thanks for wanting to pick this up! We don't assign issues to external contributors though so feel free to work on it and when you open the PR make sure to link this issue.

[bilgeyucel]

Thanks for working on this, @A-Amini! Here's the integration page with up-to-date examples: https://haystack.deepset.ai/integrations/ragas

[SyedShahmeerAli12]

Hi @sjrl @bilgeyucel this PR is ready for review whenever you have a chance. It fixes #285 by updating the rag_eval_ragas cookbook for the ragas>=0.4.3 breaking changes (now that deepset-ai/haystack-core-integrations#3207 is merged).