Align the lockstep step with the repository's established dev-image
tag-update convention instead of the force-pushed long-lived branch:
- timestamped ci/update-query-regression-epoch-YYYYMMDDHHMMSS branch
per rebuild, plain (non-force) push
- fresh PR per rebuild with the same reviewer list as the dev-builder
script, plus WenyXu (query-regression runner owner)
- bot identity greptimedb-ci@greptime.com and a signed commit,
matching .github/scripts/update-dev-builder-version.sh
The QUERY_REGRESSION_ECS_IMAGE_ID variable still updates only after
the PR exists (same-toolchain swaps are cache-ABI-safe).
Signed-off-by: Ning Sun <sunning@greptime.com>