[CI] Refine nightly pytest command in Omni · Function Test with H100 to avoid duplicate testing. (#3459)

Signed-off-by: wangyu <410167048@qq.com>

.buildkite/test-nightly.yml

@@ -13,7 +13,7 @@ steps:
       - label: ":full_moon: Omni · Function Test with H100"
         timeout_in_minutes: 90
         commands:
-          - pytest -s -v tests/e2e/ -m "full_model and H100 and omni" --run-level "full_model" --ignore=tests/e2e/accuracy
+          - pytest -sv tests/e2e --run-level "full_model" -m "full_model and H100 and omni" --ignore=tests/e2e/accuracy --ignore=tests/e2e/online_serving/test_qwen3_omni_multi_replicas.py
         agents:
           queue: "mithril-h100-pool"
         plugins: