Use register-gen to generate schema registration boilerplate

[twz123]

Description

Replace the handwritten stuff with that.

See:

• Improvements to Kubernetes related code generation #2909

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

How Has This Been Tested?

• Manual test
• Auto test added

Checklist:

• My code follows the style guidelines of this project
• My commit messages are signed-off
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• I have checked my code and corrected any misspellings

The merge-base changed after approval.

[github-actions]

This pull request has merge conflicts that need to be resolved.

[twz123]

This is basically creating zz_generated.register.go files for each API version using this template: https://github.com/kubernetes/kubernetes/blob/v1.30.1/staging/src/k8s.io/code-generator/cmd/register-gen/generators/register_external.go#L75-L116.