[Doc] eval-type not support service but server (#2920)

### What this PR does / why we need it?
fix wrong eval-type in accuracy doc

- vLLM version: v0.10.2
- vLLM main:
fec347dee1

Signed-off-by: root <root@liaolile-laptop.localdomain>
Co-authored-by: root <root@liaolile-laptop.localdomain>

docs/source/developer_guide/evaluation/using_evalscope.md

@@ -72,7 +72,7 @@ evalscope eval \
  --model Qwen/Qwen2.5-7B-Instruct \
  --api-url http://localhost:8000/v1 \
  --api-key EMPTY \
- --eval-type service \
+ --eval-type server \
  --datasets gsm8k \
  --limit 10
 ```