[Refactor] cache cos/sin in mla & remove parameter model in builder. (#5277)

RFC: https://github.com/vllm-project/vllm-ascend/issues/4629

1. Cache cos/sin in mla
2. AttentionBuilder inherits from the original class of vllm.



version: release/v0.13.0
- vLLM main:
ad32e3e19c

---------

Signed-off-by: weijinqian_v1 <weijinqian@huawei.com>
Co-authored-by: weijinqian_v1 <weijinqian@huawei.com>

vllm_ascend/attention/attention_cp.py

@@ -20,7 +20,6 @@ from typing import ClassVar, List, Optional, Tuple
 import numpy as np
 import torch
 import torch.distributed as dist
-import torch.nn as nn
 import torch_npu
 from vllm.config import VllmConfig
 from vllm.distributed import (get_dcp_group,
@@ -90,7 +89,7 @@ class AscendAttentionCPMetadataBuilder(AscendAttentionMetadataBuilder):
         self,
         common_prefix_len: int,
         common_attn_metadata: AscendCommonAttentionMetadata,
-        model: Optional[nn.Module] = None,
+        fast_build: bool = False,
     ):
         num_reqs = common_attn_metadata.num_reqs
         num_actual_tokens = common_attn_metadata.num_actual_tokens