Judge scoring failing when the env forwards kwargs

[ob1-s]

I noticed toxicity-explanation and continuation-quality scoring is failing due to the environment forwarding **kwargs to the JudgeRubric.judge call.

2026-01-09 13:40:00 - verifiers.rubrics.rubric.JudgeRubric - ERROR - Error calling reward function grade_reward: JudgeRubric.judge() got an unexpected keyword argument 'task'

[willccbb]

Fixed by #721