### What this PR does / why we need it?
1. Increase nightly multi-node test max-parallel from 1 to 2, and fix
resource conflicts that arise when tests run concurrently.
2. Fix parse-trigger job: Add an if condition so it only runs on
schedule, workflow_dispatch, or PRs labeled nightly-test
3. Adjust nightly schedule: Shift trigger time from 24:00 to 23:45
(UTC+8)
### Does this PR introduce _any_ user-facing change?
### How was this patch tested?
- vLLM version: v0.16.0
- vLLM main:
4034c3d32e
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Signed-off-by: hfadzxy <starmoon_zhang@163.com>
67d40f23fd