Remove unused row_idx in token_dispatcher (#3442)

### What this PR does / why we need it?
The `row_idx` parameter is no longer used since
PR[#2689](https://github.com/vllm-project/vllm-ascend/pull/2689), so
remove it across multiple files to remove unnecessary calculations and
parameter passing.

### Does this PR introduce _any_ user-facing change?
No
### How was this patch tested?
accuracy test passed for Qwen3 235B and DeepSeek V3 671B after this PR.


- vLLM version: v0.11.0rc3
- vLLM main: https://github.com/vllm-project/vllm/commit/v0.11.0

---------

Signed-off-by: CaranLic <740821011@qq.com>

vllm_ascend/ops/common_fused_moe.py

@@ -110,7 +110,7 @@ class AscendUnquantizedFusedMoEMethod(UnquantizedFusedMoEMethod):
               shared_experts: Optional[Any] = None,
               **kwargs) -> torch.Tensor:
 
-        topk_weights, topk_ids, row_idx = select_experts(
+        topk_weights, topk_ids = select_experts(
             hidden_states=x,
             router_logits=router_logits,
             top_k=top_k,
@@ -138,7 +138,6 @@ class AscendUnquantizedFusedMoEMethod(UnquantizedFusedMoEMethod):
             w2=layer.w2_weight,
             topk_weights=topk_weights,
             topk_ids=topk_ids,
-            row_idx=row_idx,
             global_num_experts=global_num_experts,
             expert_map=expert_map,
             shared_experts=shared_experts,