[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/attention/utils.py

@@ -21,6 +21,13 @@ class AscendCommonAttentionMetadata:
     """(batch_size,), the length of each request including both computed tokens
     and newly scheduled tokens"""
 
+    seq_lens: torch.Tensor
+    """same to seq_lens_cpu, for compatibility with some new attn metadata
+    (such as GDN)."""
+
+    num_computed_tokens_cpu: torch.Tensor
+    """(batch_size,), the number of computed tokens for each request"""
+
     num_reqs: int
     """Number of requests"""
     num_actual_tokens: int