Clean up the duplicated (and problematic) "generate-go-crd-clients"

[yuwenma]

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• I did not find a related open enhancement request.
• I understand that enhancement requests filed in the GitHub repository are by default low priority.
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Describe the feature or resource

This issue is for tracking purpose

This originated from triaging a bug that block promoting a KMS Alpha resource to Beta (direct), where the KMS services have both TF and direct resources in both Alpha and Beta versions, and the autogenerated client cannot import the autogenerated API (alpha), when promoting alpha to beta and keep the alpha CRD. It turns out that the bug comes from generate-go-crd-clients where it cannot support auto-generating APIs with multiple CRD versions. Instead, it deletes the autogenerated alpha API.

The real problem is that the generate-go-crd-clients generates the api and go client lib using go template, rather than relying on the sig-k8s its own solution (controller-gen).

As we migrating to the new "direct" approach, we are using the controller-gen to build the api client and can now support multiple CRD versions. However, the generate-go-crd-clients is still there in the presubmit infra, generating duplicate code and blocks the new direct resources.

We want to remove it from the presubmit infra immediately to unblock new resources. But we cannot delete the existing auto-generate code because OSS users may still need it.

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