fix: bump langchain from 0.3.27 to 1.3.9 in /packages/bigframes

Bumps [langchain](https://github.com/langchain-ai/langchain) from 0.3.27 to 1.3.9.
- [Release notes](https://github.com/langchain-ai/langchain/releases)
- [Commits](langchain-ai/langchain@langchain==0.3.27...langchain==1.3.9)

---
updated-dependencies:
- dependency-name: langchain
  dependency-version: 1.3.9
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

packages/bigframes/testing/constraints-3.11.txt

@@ -265,7 +265,7 @@ keras-nlp==0.21.1
 keyring==25.6.0
 keyrings.google-artifactregistry-auth==1.1.2
 kiwisolver==1.4.8
-langchain==0.3.27
+langchain==1.3.9
 langchain-core==0.3.72
 langchain-text-splitters==0.3.9
 langcodes==3.5.0