chore: Add AddToScheme pattern to v1 API version

[zamai]

Description
Many Kubernetes controllers and integration tests rely on AddToScheme helpers to register CRDs. Adding this function to Karpenter simplifies setup, and aligns with standard Kubernetes API patterns.

This PR adds AddToScheme support for Karpenter API types, enabling them to be registered with a runtime.Scheme. This makes it straightforward for external controllers, tests, and tools to use Karpenter’s types with controller-runtime clients, decoders, and webhooks without manual type registration.

Example how currently I register these types:

      // Manually register Karpenter types since it doesn't export AddToScheme
	karpenterGV := schema.GroupVersion{Group: "karpenter.sh", Version: "v1"}
	metav1.AddToGroupVersion(s, karpenterGV)
	s.AddKnownTypes(karpenterGV,
		&karpenterv1.NodePool{},
		&karpenterv1.NodePoolList{},
		&karpenterv1.NodeClaim{},
		&karpenterv1.NodeClaimList{},
	)

After Fix:

	s := runtime.NewScheme()
        karpenterv1.AddToScheme(s)

How was this change tested?
Manually, and I've generated some tests locally, but I feel that they might be unnecessary in the repo.

Please let me know if adding tests for this variable would a requirement, to merge.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

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[coveralls]

Pull Request Test Coverage Report for Build 19195221923

Details

• 0 of 10 (0.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.04%) to 81.651%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pkg/apis/v1/register.go	0	10	0.0%

Totals
Change from base Build 19111740812:	-0.04%
Covered Lines:	11583
Relevant Lines:	14186

---

💛 - Coveralls

[zamai]

/retest

[k8s-ci-robot]

@zamai: Cannot trigger testing until a trusted user reviews the PR and leaves an /ok-to-test message.

In response to this:

/retest

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[DerekFrank]

nit: How do you feel about:

Suggested change

	func addKnownTypes(s *runtime.Scheme) error {
	func (s *runtime.Scheme) addKnownTypes() {

[zamai]

I feel okay about it, but I used runtime.NewSchemeBuilder which accepts function with this signature:

NewSchemeBuilder(funcs ...func(*Scheme) error) SchemeBuilder 

I was following the same pattern I saw other packages implement, example:
https://github.com/argoproj/argo-rollouts/blob/92f4801475175abc888f7a29fee63fd965e15c14/pkg/apis/rollouts/v1alpha1/register.go#L35

[DerekFrank]

Do you have any examples of controllers that follow this type of pattern that could be refactored?

[DerekFrank]

If i'm not mistaken, this includes several different options for adding known types, as you could call:

v1.SchemeBuilder.Build()

as well. Is this intentional?

[zamai]

It was intentionally copping this registration from go-client:
https://github.com/kubernetes/client-go/blob/d9e3e97bc805a0a2936112b8a33b78be27b09eec/scale/scheme/register.go

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: moko-poi, zamai
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