fix: when delete resource if no CRD in the cluster

[zdtsw]

• for Removed, resource wont get removed since CRD not exist, resource wont exists as well.
• thanks @ykaliuta pointed to the error for this case

Description

ref: https://issues.redhat.com/browse/RHOAIENG-8297

How Has This Been Tested?

Merge criteria:

• The commits are squashed in a cohesive manner and have meaningful messages.
• Testing instructions have been added in the PR body (for PRs involving changes that are not immediately obvious).
• The developer has manually tested the changes and verified that the changes work

[ykaliuta]

Could it be ok to return new NotFound? Argumentation is the same as af749ec

[zdtsw]

should we just handle the notfound directly in the getResource()?
and we
e.g

func getResource(ctx context.Context, cli client.Client, obj *unstructured.Unstructured) (*unstructured.Unstructured, error) {
	found := &unstructured.Unstructured{}
	// Setting gvk is required to do Get request
	found.SetGroupVersionKind(obj.GroupVersionKind())
	err := cli.Get(ctx, types.NamespacedName{Name: obj.GetName(), Namespace: obj.GetNamespace()}, found)
	if err != nil {
		if errors.Is(err, &meta.NoKindMatchError{}) {
			return nil, nil // ignore mising CRD error
		}
		if client.IgnoreNotFound(err) == nil {
			return nil, nil // not found resource
		}
		return nil, err
	}
	return found, nil
}

for the caller:

	// Return if error getting resource in cluster
	found, err := getResource(ctx, cli, obj); 
	if err != nil {
		return err
	}

[ykaliuta]

This will work, but I do not like the idea to return nil object with nil error. It's prone to mistakes. But I do not have a strong opinion. Let's ask one more point of view? :) @bartoszmajsak

[bartoszmajsak]

@zdtsw @ykaliuta In my opinion, returning nil, nil can cause more harm than good. The response should either be the requested item or an error. This way, you only need to check for nil in the case of an error, allowing you to handle exceptions appropriately. Otherwise, we risk cluttering the codebase with nil checks or encountering nil pointer errors at runtime, as the caller may assume the returned instance is valid if the error is nil. Therefore, I believe it is preferable to return apierrs.NewNotFound as @ykaliuta suggests.

[zdtsw]

follow up in #1045 to address comments.

[openshift-ci]

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