chore(deps): bump langgraph in /samples/mcp-functions-agent

Bumps [langgraph](https://github.com/langchain-ai/langgraph) from 0.5.4 to 1.0.10rc1.
- [Release notes](https://github.com/langchain-ai/langgraph/releases)
- [Commits](langchain-ai/langgraph@0.5.4...1.0.10rc1)

---
updated-dependencies:
- dependency-name: langgraph
  dependency-version: 1.0.10rc1
  dependency-type: direct:production
...

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

Author: dependabot[bot]