What is the feature and why do you need it:

OpenAPI Generator has got some improvements that we should pull in. Doing that will resolve issues like #859, #1131.

Risks

There have a lot!! of changes since v4.3.0. We would need to go through most of those changes through the release notes and see if anything can break the client.

Describe the solution you'd like to see:

Update OpenAPI Generator to v5.3.0 in https://github.com/kubernetes-client/gen/blob/a3aef4de7a1d5dab72021aa282fffd8bc8a022ca/openapi/python.sh#L48