[Rebase] Align vLLM-Omni with vLLM v0.31.0 (#8459)

Signed-off-by: tzhouam <tzhouam@connect.ust.hk>

docs/configuration/README.md

@@ -2,7 +2,7 @@
 
 This section lists the most common options for running vLLM-Omni.
 
-For options within a vLLM Engine, please refer to the [vLLM 0.30 configuration guide](https://docs.vllm.ai/en/v0.30.0/configuration/index.html).
+For options within a vLLM Engine, please refer to the [vLLM 0.31 configuration guide](https://docs.vllm.ai/en/v0.31.0/configuration/index.html).
 
 Each model defines fixed topology in a registered `PipelineConfig` and runtime
 overrides in a deploy YAML.

docs/configuration/environment_variables.md

@@ -186,7 +186,7 @@ their keys only.
 ## Inherited vLLM variables
 
 vLLM-Omni also reads variables through its aligned vLLM dependency. Refer to
-the [vLLM 0.30 environment-variable reference](https://docs.vllm.ai/en/v0.30.0/configuration/env_vars.html)
+the [vLLM 0.31 environment-variable reference](https://docs.vllm.ai/en/v0.31.0/configuration/env_vars.html)
 for their definitions. This includes vLLM launch, cache, logging, plugin, ROCm,
 XPU, ModelScope, and FlashInfer workspace settings.