Bump langchain-community in /functions/most_popular_repo_langchain

Bumps [langchain-community](https://github.com/langchain-ai/langchain) from 0.3.4 to 0.3.8.
- [Release notes](https://github.com/langchain-ai/langchain/releases)
- [Commits](langchain-ai/langchain@langchain-community==0.3.4...langchain-community==0.3.8)

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

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

functions/most_popular_repo_langchain/requirements.txt

@@ -1,5 +1,5 @@
 langchain==0.3.6
-langchain-community==0.3.4
+langchain-community==0.3.8
 requests==2.32.3
 PyGithub==2.4.0
 boto3==1.35.53