Revert "remove wrong interleave"

This reverts commit b143db2.

Author: dongfengy

tensorrt_llm/_torch/models/modeling_gpt_oss.py

@@ -794,6 +794,17 @@ def load_nvfp4_weights(self, weights: Dict):
                 gate_up_bias = module_weights.get('gate_up_proj_bias', None)
                 down_bias = module_weights.get('down_proj_bias', None)
 
+                # Optional deinterleave for checkpoints that interleave gate/up
+                if gate_up is not None and gate_up.dim() == 3:
+                    try:
+                        g, u = gate_up[:, :, ::2], gate_up[:, :, 1::2]
+                        gate_up = torch.cat([g, u], dim=-1)
+                        if gate_up_bias is not None:
+                            gb, ub = gate_up_bias[:, ::2], gate_up_bias[:, 1::2]
+                            gate_up_bias = torch.cat([gb, ub], dim=-1)
+                    except Exception:
+                        pass
+
                 # Only fp32 bias is supported for NVFP4 MoE.
                 if gate_up_bias.dtype != torch.float32:
                     gate_up_bias = gate_up_bias.to(torch.float32)