Ability to skip rollout and load cached responses

[mikasenghaas]

Would be super useful for debugging a rubric and unit testing if we one could bypass the rollout function and simply load past responses, probably from results.jsonl file in outputs.

[ob1-s]

+1 on that. esp with different env args. In my case i have an env where the parser behaves differently to support thinking models, and i forgot one too many times to enable the think flag :'(

i.e.

# on load_environment
if use_think:
    parser = vf.ThinkParser()
else:
    parser = vf.Parser()

would be happy to open a PR if it makes sense.