Improve management of number of requests per second when running in batch

[cesr]

Depending on the provider sometimes it's easy to hit api rate limits. We should do a better job at managing this.

[thiwa8]

This happens for fairly large request when using claude sonnet 3.5 AND 3.7.
In my dataset of 100 examples approximately 9 evals ran. Just spacing the requests by half a second for long requests with anthropic should surely do the trick.

I wouldnt mind waiting for 1h to get my evals