fix(ci): anchor langflow-base version extraction in nightly docker build
The first nightly on the 1.11 workspace (tag v1.11.0.dev0, run
27253229568) failed in Build Nightly Base Package within seconds:
'Base version format is incorrect'. The extraction (uv tree, grep
langflow-base unanchored, awk field 3, first line) broke because uv
tree now prints the langflow-base workspace-root line
('langflow-base v1.11.0.dev0', two fields) before any dependency line
('langflow-base[complete] v1.11.0.dev0' under the langflow root, three
fields), so the first match yields an empty field 3 and the format
check exits 1. uv tree's stderr is discarded, which made the real
cause invisible in CI.
Anchor to the root line and take field 2 instead - the exact pattern
the langflow (main package) extraction in this same file already uses,
which is why the main-package builds passed on the same tag. Verified
both extractions print 1.11.0.dev0 against a local checkout of
v1.11.0.dev0.
0b4e186f7b