chore(deps): bump langchain-openai from 0.1.25 to 0.3.18

Bumps [langchain-openai](https://github.com/langchain-ai/langchain) from 0.1.25 to 0.3.18.
- [Release notes](https://github.com/langchain-ai/langchain/releases)
- [Commits](langchain-ai/langchain@langchain-openai==0.1.25...langchain-openai==0.3.18)

---
updated-dependencies:
- dependency-name: langchain-openai
  dependency-version: 0.3.18
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

requirements/base.txt

@@ -1,7 +1,7 @@
 
 python-decouple==3.8
 langchainhub==0.1.21
-langchain-openai==0.1.25
+langchain-openai==0.3.18
 langchain-experimental
 openai>=1.40.0
 langchain