[1/N][Draft][Refactor]torchair pangu_moe modeling refactor (#2437)

### What this PR does / why we need it?

1. Similar to #2384 , this PR add a torchair-specific modeling for
pangu.
2. Fixes a bug introduced by routed_scaling_factor in #2675 .
3. remove eager test case for pangu since there has already been a
torchair test case.

### Does this PR introduce _any_ user-facing change?

No.

### How was this patch tested?


- vLLM version: v0.10.1.1
- vLLM main:
6997a25ac6

---------

Signed-off-by: zengyanjia <z00883269@china.huawei.com>
Signed-off-by: Angazenn <supperccell@163.com>
Co-authored-by: zengyanjia <z00883269@china.huawei.com>

vllm_ascend/torchair/utils.py

@@ -173,6 +173,11 @@ def register_torchair_model():
         "Qwen3MoeForCausalLM",
         "vllm_ascend.torchair.models.qwen3_moe:CustomQwen3MoeForCausalLM")
 
+    ModelRegistry.register_model(
+        "PanguProMoEForCausalLM",
+        "vllm_ascend.torchair.models.torchair_pangu_moe:PanguProMoEForCausalLM"
+    )
+
 
 def torchair_quant_method_register():
     from vllm_ascend.quantization.quantizer import \