build(deps): Bump langgraph from 1.2.5 to 1.2.9

Bumps [langgraph](https://github.com/langchain-ai/langgraph) from 1.2.5 to 1.2.9.
- [Release notes](https://github.com/langchain-ai/langgraph/releases)
- [Commits](langchain-ai/langgraph@1.2.5...1.2.9)

---
updated-dependencies:
- dependency-name: langgraph
  dependency-version: 1.2.9
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

authbridge/requirements.txt

@@ -1,7 +1,7 @@
 python-keycloak>=7.1.1,<8
 PyYAML>=6.0.3
 
-langgraph==1.2.5
+langgraph==1.2.9
 langchain-core==1.4.9
 langchain-openai==1.3.4
 pydantic==2.13.4