[BUG] Generated clientsets/informers aren't updated

[jacobsalway]

Description

• The generated code under https://github.com/kubeflow/spark-operator/tree/master/pkg/client hasn't been updated in a while
• There is no CI check to ensure the generated code has been run if the API has been changed
• There doesn't seem to be a Makefile target to do this either. There are some scripts under hack/ that look like they were used to run the codegen in the past that could be updated.

• ✋ I have searched the open/closed issues and my issue is not listed