chore(deps): bump langchain from 0.3.4 to 0.3.30

Bumps [langchain](https://github.com/langchain-ai/langchain) from 0.3.4 to 0.3.30.
- [Release notes](https://github.com/langchain-ai/langchain/releases)
- [Commits](langchain-ai/langchain@langchain==0.3.4...langchain==0.3.30)

---
updated-dependencies:
- dependency-name: langchain
  dependency-version: 0.3.30
  dependency-type: direct:production
...

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

Author: dependabot[bot]

requirements.txt

@@ -1,4 +1,4 @@
-langchain==0.3.4
+langchain==0.3.30
 langchain-community==0.3.3
 numpy==1.26.4
 SQLAlchemy==2.0.36