Bump boto3 from 1.35.15 to 1.35.16 in /docker/boto3py3

Bumps [boto3](https://github.com/boto/boto3) from 1.35.15 to 1.35.16.
- [Release notes](https://github.com/boto/boto3/releases)
- [Commits](boto/boto3@1.35.15...1.35.16)

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

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