support tensor parallel

nanovllm/models/qwen3.py

@@ -1,5 +1,6 @@
 import torch
 from torch import nn
+import torch.distributed as dist
 from transformers import Qwen3Config
 
 from nanovllm.layers.activation import SiluAndMul
@@ -26,7 +27,7 @@ class Qwen3Attention(nn.Module):
     ) -> None:
         super().__init__()
         self.hidden_size = hidden_size
-        tp_size = 1  # get_tensor_model_parallel_world_size()
+        tp_size = dist.get_world_size()
         self.total_num_heads = num_heads
         assert self.total_num_heads % tp_size == 0
         self.num_heads = self.total_num_heads // tp_size