[Bugfix] Lazy import gpt_oss_triton_kernels_moe for mxfp4 (#23678)

Signed-off-by: mgoin <mgoin64@gmail.com>

vllm/model_executor/layers/quantization/mxfp4.py

@@ -10,8 +10,6 @@ from vllm.config import get_current_vllm_config
 from vllm.logger import init_logger
 from vllm.model_executor.layers.fused_moe import (FusedMoE, FusedMoEConfig,
                                                   FusedMoEMethodBase)
-from vllm.model_executor.layers.fused_moe.gpt_oss_triton_kernels_moe import (
-    triton_kernel_moe_forward)
 from vllm.model_executor.layers.linear import (LinearBase,
                                                UnquantizedLinearMethod)
 from vllm.model_executor.layers.quantization import QuantizationMethods
@@ -557,6 +555,8 @@ class Mxfp4MoEMethod(FusedMoEMethodBase):
             )[0]
             return trtllm_gen_output
         else:
+            from vllm.model_executor.layers.fused_moe.gpt_oss_triton_kernels_moe import (  # noqa: E501
+                triton_kernel_moe_forward)
             return triton_kernel_moe_forward(
                 hidden_states=x,
                 w1=self.w13_weight_triton_tensor,