### What this PR does / why we need it?
Add e2e test case for apply_top_k_top_p_custom kernel and eliminate
chinese comments.
### Does this PR introduce _any_ user-facing change?
No.
### How was this patch tested?
pytest passed.
- vLLM version: v0.14.1
- vLLM main:
dc917cceb8
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Signed-off-by: linfeng-yuan <1102311262@qq.com>