Cast fp32 routing weights to bf16 in the Kimi-K3 fused finalize (#38588)

python/sglang/srt/layers/k3_ar_fusion.py

@@ -371,6 +371,8 @@ def finalize_all_reduce_push_norm(
 
     state = _get_state()
     assert state is not None
+    if expert_weights.dtype != torch.bfloat16:
+        expert_weights = expert_weights.to(torch.bfloat16)
     return mod.finalize_all_reduce_push_norm(
         state.world_size,
         out,