build(deps): bump @langchain/community and langchain in /server

Removes [@langchain/community](https://github.com/langchain-ai/langchainjs). It's no longer used after updating ancestor dependency [langchain](https://github.com/langchain-ai/langchainjs). These dependencies need to be updated together.


Removes `@langchain/community`

Updates `langchain` from 0.1.37 to 1.2.27
- [Release notes](https://github.com/langchain-ai/langchainjs/releases)
- [Commits](https://github.com/langchain-ai/langchainjs/compare/0.1.37...langchain@1.2.27)

---
updated-dependencies:
- dependency-name: "@langchain/community"
  dependency-version: 
  dependency-type: indirect
- dependency-name: langchain
  dependency-version: 1.2.27
  dependency-type: direct:production
...

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Author: dependabot[bot]