[CI] Make AttentionBackend interface compatible to fix broken CI

[wangxiyuan]

vLLM commit vllm-project/vllm@752c6ad removed blocksparse_params for attention backend. This PR does the same change to make CI happy.

• vLLM version: v0.9.2
• vLLM main: vllm-project/vllm@9499e26

[codecov]

Codecov Report

Attention: Patch coverage is 64.70588% with 6 lines in your changes missing coverage. Please review.

Project coverage is 60.88%. Comparing base (2b726d8) to head (0407ffc).
Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
vllm_ascend/attention/mla_v1.py	57.14%	3 Missing ⚠️
vllm_ascend/attention/attention_v1.py	60.00%	2 Missing ⚠️
tests/ut/attention/test_attention_v1.py	80.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1893      +/-   ##
==========================================
- Coverage   60.89%   60.88%   -0.01%     
==========================================
  Files          73       73              
  Lines        8157     8171      +14     
==========================================
+ Hits         4967     4975       +8     
- Misses       3190     3196       +6     

Flag	Coverage Δ
unittests	60.88% <64.70%> (-0.01%)	⬇️

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