Bump boto3 in /functions/most_popular_repo_bedrock_agent/agent

Bumps [boto3](https://github.com/boto/boto3) from 1.40.42 to 1.40.64.
- [Release notes](https://github.com/boto/boto3/releases)
- [Commits](boto/boto3@1.40.42...1.40.64)

---
updated-dependencies:
- dependency-name: boto3
  dependency-version: 1.40.64
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

functions/most_popular_repo_bedrock_agent/agent/requirements.txt

@@ -1 +1 @@
-boto3==1.40.42
+boto3==1.40.64