OCP4: Custom Annotations applied to EgressIP objects are removed automatically

Issue

• EgressIP objects with custom annotations are observed to have the value replaced/removed after some time:

apiVersion: v1
items:
- apiVersion: k8s.ovn.org/v1
  kind: EgressIP
  metadata:
    annotations:
      test-annotation: "true" ##<---
    name: eip-testing

• After reconciliation, the controller replaces/removes the annotation with a managed value:

apiVersion: v1
items:
- apiVersion: k8s.ovn.org/v1
  kind: EgressIP
  metadata:
    annotations:
      k8s.ovn.org/egressip-mark: "50000" ##<--- test annotation replaced
    name: eip-testing