chore(deps): bump boto3 in /examples/chatbots/python

Bumps [boto3](https://github.com/boto/boto3) from 1.42.69 to 1.42.81.
- [Release notes](https://github.com/boto/boto3/releases)
- [Commits](boto/boto3@1.42.69...1.42.81)

---
updated-dependencies:
- dependency-name: boto3
  dependency-version: 1.42.81
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

examples/chatbots/python/requirements.txt

@@ -1,7 +1,7 @@
 strands-agents==1.30.0
 mcp==1.26.0
 uvicorn==0.42.0
-boto3==1.42.69
+boto3==1.42.86
 
 # For testing, this module is installed from local files.
 # Uncomment this line to build using the module from PyPi