### What this PR does / why we need it?
Previously implemention of triton rope_siso missing the storage of
second half of rope results, which will result in:
1. accuracy problem in neox-style scenario
2. ub overflow in non neox-style scenario
This PR fixes it and supplement nightly test case for it.
- vLLM version: v0.16.0
- vLLM main:
4034c3d32e
Signed-off-by: whx-sjtu <2952154980@qq.com>