build(deps): Update langchainrb requirement from ~> 0.14.0 to ~> 0.16.1

Updates the requirements on [langchainrb](https://github.com/patterns-ai-core/langchainrb) to permit the latest version.
- [Release notes](https://github.com/patterns-ai-core/langchainrb/releases)
- [Changelog](https://github.com/patterns-ai-core/langchainrb/blob/main/CHANGELOG.md)
- [Commits](patterns-ai-core/langchainrb@0.14.0...0.16.1)

---
updated-dependencies:
- dependency-name: langchainrb
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Gemfile

@@ -14,7 +14,7 @@ gem "jongleur"
 gem "json"
 gem "jsonl"
 gem "kramdown", "~> 2.4"
-gem "langchainrb", "~> 0.14.0"
+gem "langchainrb", "~> 0.16.1"
 gem "lingua"
 gem "mimemagic", "~> 0.4.3"
 gem "minitest", "~> 5.11"