fix(ci): lockstep langflow-nightly and langflow-base-nightly versions
Forward-port of #13413 (merged to release-1.10.0) to main.
pypi_nightly_tag.py now derives a single shared dev number from
max(dev across BOTH langflow-nightly and langflow-base-nightly PyPI
histories) + 1 (restricted to the root base_version) and emits it twice in
`both` mode. nightly_build.yml reads the release and base tags from one
invocation (single PyPI snapshot) and fails closed on mismatch, so the latest
langflow-nightly always pins a langflow-base-nightly[complete]==X.Y.Z.devN
that was built and published in the same run (no more uninstallable nightly).
Safe to land now: the nightly create-nightly-tag job checks out the latest
release-* branch for the script while taking the run-block from the triggering
ref (main for scheduled runs). release-1.10.0 already carries the new script
(via #13413), so main's `both` run-block matches it, and future release
branches cut from main inherit the lockstep script.
Adds scripts/ci/test_pypi_nightly_tag.py + .github/workflows/ci-scripts-test.yml
and the update_pyproject_combined.py lockstep-invariant note.
