[New model] Qwen3-next support (#2917)

### What this PR does / why we need it?
Add Qwen3-next support.

### Does this PR introduce _any_ user-facing change?
Yes, users can use Qwen3 next.
Related doc: https://github.com/vllm-project/vllm-ascend/pull/2916 the
tutorial will be ready in
[here](https://vllm-ascend.readthedocs.io/en/latest/tutorials/multi_npu_qwen3_next.html)

### How was this patch tested?
Doc CI passed

Related: https://github.com/vllm-project/vllm-ascend/issues/2884

Co-Authored-By: Angazenn <supperccell@163.com>
Co-Authored-By: zzzzwwjj <1183291235@qq.com>
Co-Authored-By: MengqingCao <cmq0113@163.com>
Co-Authored-By: linfeng-yuan <1102311262@qq.com>
Co-Authored-By: hust17yixuan <303660421@qq.com>
Co-Authored-By: SunnyLee219 <3294305115@qq.com>
Co-Authored-By: maoxx241 <maoxx241@umn.edu>


- vLLM version: v0.10.2
- vLLM main:
b834b4cbf1

---------

Signed-off-by: MengqingCao <cmq0113@163.com>
Signed-off-by: wangxiyuan <wangxiyuan1007@gmail.com>
Signed-off-by: Angazenn <supperccell@163.com>
Signed-off-by: Your Name <you@example.com>
Signed-off-by: zzzzwwjj <1183291235@qq.com>
Signed-off-by: linfeng-yuan <1102311262@qq.com>
Signed-off-by: hust17yixuan <303660421@qq.com>
Co-authored-by: MengqingCao <cmq0113@163.com>
Co-authored-by: Angazenn <supperccell@163.com>
Co-authored-by: Your Name <you@example.com>
Co-authored-by: zzzzwwjj <1183291235@qq.com>
Co-authored-by: linfeng-yuan <1102311262@qq.com>
Co-authored-by: hust17yixuan <303660421@qq.com>

vllm_ascend/torchair/torchair_model_runner.py

@@ -50,6 +50,9 @@ class NPUTorchairModelRunner(NPUModelRunner):
 
     def __init__(self, vllm_config: VllmConfig, device: torch.device):
         super().__init__(vllm_config, device)
+        self.attn_metadata_builder = self.attn_backend.get_builder_cls()(
+            None, None, vllm_config, device)
+
         ascend_config = get_ascend_config()
         self.new_kv_cache_bytes = -1
         self.torchair_compiled_model = None  # type: ignore
@@ -278,6 +281,9 @@ class NPUTorchairModelRunner(NPUModelRunner):
                                              input_ids, positions,
                                              intermediate_tensors,
                                              inputs_embeds):
+        if attn_metadata is not None and isinstance(attn_metadata, dict):
+            attn_metadata = attn_metadata['model.layers.0.self_attn.attn']
+
         model_kwargs = {
             "kv_caches": self.kv_caches,
             "attn_metadata": attn_metadata