[TEST]Update nightly acc test standard (#4032)

### What this PR does / why we need it?
This PR updates the acc test standard for some cases, we need it to
better maintain acc

### Does this PR introduce _any_ user-facing change?
No

### How was this patch tested?
by running the test

- vLLM version: v0.11.0
- vLLM main:
83f478bb19

Signed-off-by: jiangyunfan1 <jiangyunfan1@h-partners.com>

tests/e2e/nightly/models/test_qwen3_32b_int8.py

@@ -58,7 +58,7 @@ aisbench_cases = [{
     "max_out_len": 32768,
     "batch_size": 32,
     "baseline": 83.33,
-    "threshold": 17
+    "threshold": 7
 }, {
     "case_type": "performance",
     "dataset_path": "vllm-ascend/GSM8K-in3500-bs400",