Bump bollard from 0.15.0 to 0.16.1

Bumps [bollard](https://github.com/fussybeaver/bollard) from 0.15.0 to 0.16.1.
- [Release notes](https://github.com/fussybeaver/bollard/releases)
- [Commits](fussybeaver/bollard@v0.15.0...v0.16.1)

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

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