### What this PR does / why we need it?
Currently, the nightly image is built at 20 PM and 23 PM UTC+8. Due to
some timeliness requirements, we need to add a new trigger method for
nightly image builds.
### Does this PR introduce _any_ user-facing change?
### How was this patch tested?
- vLLM version: v0.14.1
- vLLM main:
d68209402d
Signed-off-by: wangli <wangli858794774@gmail.com>