Introduce `docker-distribution-pruner version` into GitLab

What does this MR do?

This adds a proper inclusion of Docker Distribution Pruner into GitLab Toolstack. This follows the docker-distribution-pruner#20 (closed).

This is needed by omnibus-gitlab#4021 (closed) to be able to build a specific version of application, not latest version.

What are the relevant issue numbers?

Related to omnibus-gitlab#4021 (closed).

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• Tests added for this feature/bug
• Tested in all supported browsers
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides
• Link to e2e tests MR added if this MR has Requires e2e tests label. See the Test Planning Process.
• Security reports checked/validated by reviewer