Slow Reconciliation and Target Disappearance on Gateway Port Changes

Describe the bug
When making port changes in a Gateway specification, the reconciliation process to VPC Lattice control plane takes an excessive amount of time. During this process, existing target groups disappear from the control plane but new targets with updated ports are not registered until the gateway configuration is manually reapplied.

To Reproduce
Steps to reproduce the behavior:

1. Deploy a Gateway with specific port configuration in the spec
2. Make a port change in the Gateway specification file
3. Apply the updated Gateway configuration using kubectl apply
4. Monitor the VPC Lattice control plane for target group registration
5. Observe that registered target groups disappear but new targets with updated ports are not automatically registered

Expected behavior

• The controller should efficiently reconcile the changes to VPC Lattice
• Old target groups should be gracefully transitioned to new port configurations
• New targets should be automatically registered with the updated ports without requiring manual reapplication of the Gateway configuration

Additional context

• The issue specifically occurs during port changes in Gateway specifications
• Target groups completely disappear from the control plane during the reconciliation process
• Manual reapplication of the Gateway file is required to restore target registration
• This suggests a potential issue with the controller's reconciliation logic for port updates

This issue has been deprioritized based on reconciliation improvements made in #822.