[rollout] feat: Add vllm logprob mode and default processed_logprob

[RobotGF]

What does this PR do?

add logprob_mode config for vllm rollout. And set default rollout logprob mode "processed_logprobs" to return logprobs processed after temperature、Penalty、and topk topp

ref : vllm-project/vllm#22387

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[gemini-code-assist]

Code Review

This pull request introduces a logprobs_mode configuration for vLLM rollouts, defaulting to processed_logprobs. The changes are correctly implemented across the YAML configuration, the dataclass definition, and the vLLM server arguments. However, I've identified a potential runtime error due to an incorrect type hint in the configuration dataclass which could prevent users from disabling this feature. My review includes a suggestion to fix this.