Propose swagger.yaml modifications upstream

[gesellix]

Some parts of the official swagger.yaml don't match the actual api. We should propose required fixes to the upstream moby project.

• Improve swagger.yaml to match the 1.41 api version moby/moby#42621
• Default behaviour of JSON marshalling for nil slices?  moby/moby#42632: some lists aren't declared as nullable -> discuss with the moby maintainers whether to declare the properties as nullable or if moby should return a [] instead of nil.