Bump langchain-community from 0.3.18 to 0.3.20 (#94)

Bumps [langchain-community](https://github.com/langchain-ai/langchain) from 0.3.18 to 0.3.20.
- [Release notes](https://github.com/langchain-ai/langchain/releases)
- [Commits](langchain-ai/langchain@langchain-community==0.3.18...langchain-community==0.3.20)

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

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

requirements.txt

@@ -1,6 +1,6 @@
 beautifulsoup4==4.13.3
 langchain-couchbase==0.2.4
-langchain-community==0.3.18
+langchain-community==0.3.21
 langchain-openai==0.3.12
 langsmith==0.3.24
 python-dotenv==1.1.0