[feat] add val_generations_to_log_to_swanlab

[Zeyi-Lin]

In this PR, a val_generations_to_log_to_swanlab parameter has been added. When this parameter is set to 1, it supports logging the generated text from eval in SwanLab.

@hiyouga

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This pull request introduces logging of validation generations to Swanlab in addition to Wandb. The changes include updates to several configuration files and the addition of a new logging method in the ray_trainer.py file.

Key changes include:

Configuration Updates:

• Added val_generations_to_log_to_swanlab parameter to the trainer section in the following configuration files:
  • examples/split_placement/config/ppo_trainer_split.yaml
  • verl/trainer/config/ppo_megatron_trainer.yaml
  • verl/trainer/config/ppo_trainer.yaml

Code Updates:

• Added a new method _maybe_log_val_generations_to_swanlab to log validation samples to Swanlab in verl/trainer/ppo/ray_trainer.py
• Updated the _validate method to call the new Swanlab logging method in verl/trainer/ppo/ray_trainer.py

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