chore(deps): bump mcp from 1.17.0 to 1.20.0 in /examples/chatbots/python

Bumps [mcp](https://github.com/modelcontextprotocol/python-sdk) from 1.17.0 to 1.20.0.
- [Release notes](https://github.com/modelcontextprotocol/python-sdk/releases)
- [Changelog](https://github.com/modelcontextprotocol/python-sdk/blob/main/RELEASE.md)
- [Commits](modelcontextprotocol/python-sdk@v1.17.0...v1.20.0)

---
updated-dependencies:
- dependency-name: mcp
  dependency-version: 1.20.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

examples/chatbots/python/requirements.txt

@@ -1,5 +1,5 @@
 aiobotocore[boto3]==2.25.0
-mcp==1.17.0
+mcp==1.20.0
 uvicorn==0.37.0
 
 # For testing, this module is installed from local files.