[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>

tests/e2e/multicard/test_torchair_graph_mode.py

@@ -22,8 +22,6 @@ Run `pytest tests/multicard/test_torchair_graph_mode.py`.
 import os
 from typing import Dict
 
-import pytest
-
 from tests.e2e.conftest import VllmRunner
 
 os.environ["PYTORCH_NPU_ALLOC_CONF"] = "max_split_size_mb:256"
@@ -155,7 +153,6 @@ def _pangu_torchair_test_fixture(
         print(f"Generated text: {vllm_output[i][1]!r}")
 
 
-@pytest.mark.skip("pangu doesn't work, fix me")
 def test_e2e_pangu_with_torchair():
     additional_config = {
         "torchair_graph_config": {