migrate addon-manager tests to use Ginkgo v2

[tekenstam]

Is this a BUG REPORT or FEATURE REQUEST?:

FEATURE REQUEST

What happened:

addon-manager is still using Ginkgo v1, which is EOL. Need to update to Ginkgo v2.

What you expected to happen:

Follow the Ginkgo v2 Migration Guide.

Anything else we need to know?:

Environment:

• Addon Manager version
• Kubernetes version :

$ kubectl version -o yaml

Other debugging information (if applicable):

• Addon status:

$ kubectl describe addon <addon-name>

• controller logs:

$ kubectl logs <addon-manager-pod>