Bump langchain-couchbase from 0.3.0 to 0.4.0 (#110)

Bumps [langchain-couchbase](https://github.com/Couchbase-Ecosystem/langchain-couchbase) from 0.3.0 to 0.4.0.
- [Release notes](https://github.com/Couchbase-Ecosystem/langchain-couchbase/releases)
- [Commits](Couchbase-Ecosystem/langchain-couchbase@langchain-couchbase==0.3.0...langchain-couchbase==0.4.0)

---
updated-dependencies:
- dependency-name: langchain-couchbase
  dependency-version: 0.4.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

requirements.txt

@@ -1,5 +1,5 @@
 beautifulsoup4==4.13.4
-langchain-couchbase==0.3.0
+langchain-couchbase==0.4.0
 langchain-community==0.3.24
 langchain-openai==0.3.27
 langsmith==0.4.4