Operatorless Istio migration leaves orphaned LoadBalancer services

Motivation

The engineering services team has noticed post-migration to operatorless istio that a LoadBalancer Service is being left behind in the istio-system Namespace pointing to the gateways deployed by the operator. This should not be here as orphaned LoadBalancers do incur cloud costs.

Acceptance Criteria

• If the issue can be reproduced and the cause mitigated, instructions for how to do that must be incorporated into the migration docs
• If the issue can not be reproduced or no mitigation is apparent, instructions must be added to the migration docs telling consumers to destroy any lingering Services in the istio-system Namespace related to old gateways