Bump langchain from 1.0.3 to 1.1.2

Bumps [langchain](https://github.com/langchain-ai/langchain) from 1.0.3 to 1.1.2.
- [Release notes](https://github.com/langchain-ai/langchain/releases)
- [Commits](langchain-ai/langchain@langchain==1.0.3...langchain==1.1.2)

---
updated-dependencies:
- dependency-name: langchain
  dependency-version: 1.1.2
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

dev_requirements.txt

@@ -1,6 +1,6 @@
 PySide6==6.10.0
 langchain_openai==1.0.2
-langchain==1.0.3
+langchain==1.1.2
 ruff
 sphinx
 twine