[Doc] Add qwen3 embedding 8b guide (#1734)

1. Add the tutorials for qwen3-embedding-8b
2. Remove VLLM_USE_V1=1  in docs, it's useless any more from 0.9.2


- vLLM version: v0.9.2
- vLLM main:
5923ab9524

Signed-off-by: wangxiyuan <wangxiyuan1007@gmail.com>

docs/source/tutorials/single_npu_audio.md

@@ -29,9 +29,6 @@ docker run --rm \
 Setup environment variables:
 
 ```bash
-# Use vllm v1 engine
-export VLLM_USE_V1=1
-
 # Load model from ModelScope to speed up download
 export VLLM_USE_MODELSCOPE=True