[bug fix][pp] fix qwen3 model load (#15223)

Signed-off-by: Xuchun Shang <xuchun.shang@gmail.com>

python/sglang/srt/models/qwen3.py

@@ -392,13 +392,13 @@ class Qwen3ForCausalLM(nn.Module):
         if self.pp_group.world_size > 1 and config.tie_word_embeddings:
             if self.pp_group.is_first_rank:
                 self.pp_group.send(
-                    self.model.embed_tokens.weight, dst=self.pp_group.last_rank
+                    self.model.embed_tokens.weight, dst=self.pp_group.world_size - 1
                 )
             elif self.pp_group.is_last_rank:
                 emb_token_weight = self.pp_group.recv(
-                    size=(config.vocab_size, config.hidden_size),
+                    size=self.lm_head.weight.shape,
                     dtype=next(self.model.parameters()).dtype,
-                    src=self.pp_group.first_rank,
+                    src=0,
                 )
                 self.lm_head.weight.copy_(emb_token_weight)