[Tiny Fix] Filter lru related warning with pcg (#20940)

Signed-off-by: yuweia <ayw.sirius19@gmail.com>

python/sglang/srt/model_executor/piecewise_cuda_graph_runner.py

@@ -18,6 +18,7 @@ from __future__ import annotations
 import bisect
 import gc
 import logging
+import warnings
 from contextlib import contextmanager
 from dataclasses import dataclass
 from typing import TYPE_CHECKING, Optional, Union
@@ -59,6 +60,8 @@ from sglang.srt.model_executor.forward_batch_info import (
 from sglang.srt.model_executor.input_buffers import ForwardInputBuffers
 from sglang.srt.utils import get_available_gpu_memory, is_npu, log_info_on_rank0
 
+# Suppress Dynamo warning about tracing through lru_cache-wrapped functions (e.g., is_arch_support_pdl).
+warnings.filterwarnings("ignore", message=".*lru_cache.*", module="torch._dynamo")
 logger = logging.getLogger(__name__)
 
 if TYPE_CHECKING: