Use distribution v3

[jkroepke]

Is your feature request related to a problem? Please describe.

My open PR #2223 about Azure Backend depends on v3 Distribution yet.

v3 is not mark as stable yet, but dev doesn’t recommend to use v2 anymore:

distribution/distribution#4382 (comment)
.

Describe the solution you'd like

Please upgrade to v3 Distribution that my PR can be merged

Describe alternatives you've considered

Additional context

No response

[rchincha]

@jkroepke very interested in your PR #2223

Let's target this for v2.1.0

^ this release train is upon us now.

But how does one separate the go.mod update from the PR, seems like a hard dependency. I would just add it as a separate commit to the same PR. I suspect resolving the go dep hell will take some work.

[jkroepke]

I hope, zot have a good test coverage.