Bump langchain from 0.0.197 to 0.0.246

Bumps [langchain](https://github.com/langchain-ai/langchain) from 0.0.197 to 0.0.246.
- [Release notes](https://github.com/langchain-ai/langchain/releases)
- [Commits](https://github.com/langchain-ai/langchain/commits)

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

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

requirements.txt

@@ -1,4 +1,4 @@
-langchain==0.0.197
+langchain==0.0.246
 gpt4all==0.3.2
 chromadb==0.3.23
 llama-cpp-python==0.1.50