[ray] feat: add support for ray init kwargs (#3049)

### What does this PR do?

This PR adds support for passing parameters to `ray.init`.
Users can now dynamically configure settings such as `address`, `port`,
`_temp_dir`, and more based on their specific needs.

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### Test

```bash
# when /tmp/ray/ is used by others
# when ray is initialized at 6379 by others
# when the dashboard is not accessible at localhost
# ...
bash examples/grpo_trainer/run_qwen2_5_vl-7b.sh \
    +ray_kwargs.ray_init._temp_dir=/tmp/ray/my_dir \
    +ray_kwargs.ray_init.address=127.0.0.1:6378 \
    +ray_kwargs.ray_init.dashboard_host=0.0.0.0
```

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recipe/dapo/main_dapo.py

@@ -36,12 +36,15 @@ def main(config):
 def run_ppo(config) -> None:
     if not ray.is_initialized():
         # this is for local ray cluster
-        ray.init(
-            runtime_env={
-                "env_vars": {"TOKENIZERS_PARALLELISM": "true", "NCCL_DEBUG": "WARN", "VLLM_LOGGING_LEVEL": "WARN"}
-            },
-            num_cpus=config.ray_init.num_cpus,
-        )
+        default_runtime_env = {
+            "env_vars": {"TOKENIZERS_PARALLELISM": "true", "NCCL_DEBUG": "WARN", "VLLM_LOGGING_LEVEL": "WARN"}
+        }
+        ray_init_kwargs = config.ray_kwargs.get("ray_init", {})
+        runtime_env_kwargs = ray_init_kwargs.get("runtime_env", {})
+        runtime_env = OmegaConf.merge(default_runtime_env, runtime_env_kwargs)
+        ray_init_kwargs = OmegaConf.create({**ray_init_kwargs, "runtime_env": runtime_env})
+        print(f"ray init kwargs: {ray_init_kwargs}")
+        ray.init(**OmegaConf.to_container(ray_init_kwargs))
 
     if (
         is_cuda_available