Fix docker engine v20.10.6 compatibility

[frozenbonito]

Description

Add Handling for IPv6 line of docker port output.

Starting with docker engine v20.10.6, docker port outputs not only IPv4 mappings but also IPv6 mappings.

e.g.:

$ docker port container
9001/tcp -> 0.0.0.0:49153
9001/tcp -> :::49153

https://docs.docker.com/engine/release-notes/#20106

Fix implicit IPv6 port-mappings not included in API response. Before docker 20.10, published ports were accessible through both IPv4 and IPv6 by default, but the API only included information about the IPv4 (0.0.0.0) mapping moby/moby#42205

The container port parsing has been broken by the IPv6 mapping line.

Motivation and Context

Failing tests on master, visible e.g. here: https://github.com/dherault/serverless-offline/runs/2438945825?check_suite_focus=true

How Has This Been Tested?

Automated tests.

[pgrzesik]

Looks good overall, just one minor comment about potential improvement to readability/understandability

[pgrzesik]

I think it would be great to add a comment with explanation as to why it's parsed this way so when someone later looks at it will right away understand what's going on, otherwise it might be hard to comprehend

[frozenbonito]

Thank you for comment.
I added comments to help someone understand it.