CRD version properties are inadvertently removed when serializing

## Summary

I am loading a `V1CustomResourceDefinition`, making a small modification to it, then re-serializing it, and I am seeing numerous unintended mutations / removals made to the resulting output CRD

Similar defect as:
- https://github.com/kubernetes-client/python/issues/2435

## Details

Here are the sequence of diffs for my CRD:

```
@@ -17,111 +16,12 @@

group: mycr.me.com
names:
kind: MyCR
- listKind: MyCRList
plural: mycrs
singular: mycr

...

- ... (Removed additionalPrinterColumns)
- ... (Removed the entire version schema)
+ - name: v1beta1
+ schema: {}
```