Bump langchain from 0.1.11 to 0.1.12

Bumps [langchain](https://github.com/langchain-ai/langchain) from 0.1.11 to 0.1.12.
- [Release notes](https://github.com/langchain-ai/langchain/releases)
- [Commits](langchain-ai/langchain@v0.1.11...v0.1.12)

---
updated-dependencies:
- dependency-name: langchain
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

requirements.txt

@@ -1,7 +1,7 @@
 black==24.2.0
 fastapi==0.110.0
 flake8==7.0.0
-langchain==0.1.11
+langchain==0.1.12
 ollama==0.1.7
 openai==1.13.3
 pre-commit==3.6.2