[VPA] Admission cert reloader use a hardcoded MutatingWebhookConfiguration name

[vflaux]

Which component are you using?:

VPA admission controller

/area vertical-pod-autoscaler

What version of the component are you using?:

Component version: v1.4.1

What k8s version are you using (kubectl version)?:

kubectl version Output

$ kubectl version
Client Version: v1.33.1
Kustomize Version: v5.6.0
Server Version: v1.32.3-eks-4096722

What environment is this in?:

AWS EKS

with the following flag:

• --register-webhook=false
• --reload-cert=true

What did you expect to happen?:

The controller should not try to update the MutatingWebhookConfiguration because --register-webhook=false.

What happened instead?:

The controller try to get the vpa-webhook-config MutatingWebhookConfiguration which doesn't exists in our environment (it is named differently).
However, the certificates should be reloaded successfully.

How to reproduce it (as minimally and precisely as possible):

Run the admision controller with --register-webhook=false & --reload-cert=true and without a vpa-webhook-config MutatingWebhookConfiguration in the cluster.
Modify the cert CA to trigger a reload.

Anything else we need to know?:

We use cert-manager to create the certificates and update the MutatingWebhookConfiguration, so there is no need for the admission controller to update it.

[omerap12]

/triage accepted