Test: waive intermittent test hang (NVIDIA#3894)

Signed-off-by: Yanchao Lu <yanchaol@nvidia.com>

Author: chzblych

tests/integration/test_lists/waives.txt

@@ -488,3 +488,4 @@ accuracy/test_cli_flow.py::TestLlama3_1_8BInstruct::test_medusa_fp8_prequantized
 accuracy/test_llm_api_pytorch.py::TestLlama3_3_70BInstruct::test_fp8_tp4 SKIP (https://nvbugs/5238602)
 unittest/_torch/multi_gpu_modeling/test_llama4.py::test_llama4[tp8-trtllm-scout] SKIP (https://nvbugs/5244009)
 accuracy/test_llm_api_pytorch.py::TestLlama3_1_8BInstruct::test_bfloat16_4gpus[tp2pp2-attn_backend=TRTLLM] SKIP (https://nvbugs/5241627)
+accuracy/test_llm_api_pytorch.py::TestLlama3_1_8BInstruct::test_bfloat16_4gpus[tp2pp2-attn_backend=FLASHINFER] SKIP (https://nvbugs/5241627)