[CI] update send_request.py test_single_node.py aisbench.py;add spec_decode_metrics.py (#14667)

### What this PR does / why we need it?
I optimized context boundary validation and acceptance rate verification
tests for single-node and multi-node nightly pipelines, and introduced
one weekly test case: Minimax-M2.5-w8a8-QuaRot.yaml.

### Does this PR introduce _any_ user-facing change?
optimized context boundary validation and acceptance rate verification
tests for single-node and multi-node nightly pipelines

### How was this patch tested?
run the cases nightly


- vLLM main:
https://github.com/vllm-project/vllm/commit/ba07e4a48fc951300d97eb506217dd530583dea3

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Signed-off-by: guxin108 <1252896542@qq.com>