[https://nvbugs/5470769][fix] fix disagg-serving accuracy test case (#7338)

Signed-off-by: Lizhi Zhou <[email protected]>

Author: reasonsolo

tests/integration/defs/accuracy/references/mmlu.yaml

@@ -203,6 +203,7 @@ Qwen3/Qwen3-8B:
   - spec_dec_algo: Eagle
     accuracy: 76.12
 Qwen3/Qwen3-30B-A3B:
+  - accuracy: 79.53
   - quant_algo: FP8_BLOCK_SCALES
     accuracy: 79.53
   - quant_algo: FP8

tests/integration/defs/accuracy/test_disaggregated_serving.py

@@ -983,4 +983,6 @@ def test_mixed_ctx_gen_model(self, ctx_pp, gen_tp):
                                  gen_tp=gen_tp,
                                  test_sets=[GSM8K, MMLU],
                                  ctx_model=ctx_model,
-                                 gen_model=gen_model)
+                                 gen_model=gen_model,
+                                 ctx_instances=1,
+                                 gen_instances=1)