Bump docker-ruby from 59bb4e0 to 3a813c1 (#7)

Bumps [docker-ruby](https://github.com/docker-library/ruby) from `59bb4e0` to `3a813c1`.
- [Commits](docker-library/ruby@59bb4e0...3a813c1)

---
updated-dependencies:
- dependency-name: docker-ruby
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]