Fix regression: use parquet metadata when possible
I noticed some datasets have a slow pagination like https://huggingface.co/datasets/mlfoundations/datacomp_1b that times out.

This is because there was a regression in https://github.com/huggingface/datasets-server/pull/1287 where it wouldn't use the parquet metadata because `get_best_response` returns the first successful response
Fix regression: use parquet metadata when possible: I noticed some datasets have a slow pagination like https://huggingface.co/datasets/mlfoundations/datacomp_1b that times out.

This is because there was a regression in https://github.com/huggingface/datasets-server/pull/1287 where it wouldn't use the parquet metadata because `get_best_response` returns the first successful response