Webhook Validation is bypassed for existing resources when NKG starts

[pleshakov]

Describe the bug
Webhook Validation is bypassed for existing resources when NKG starts.
Note: the webhook validation running inside NKG process.

To Reproduce
Make sure Webhook is not installed, so that we test the webhook validation running inside NKG process.

1. Create a resource that fails webhook validation.
2. Deploy NKG
3. See that NKG processes the resource.

Why? Because the resource is included in the first batch -- https://github.com/nginxinc/nginx-kubernetes-gateway/blob/13fc9a2428ee90648681abb22e08ef5f79d33e03/internal/events/loop.go#L92

Expected behavior

Validation is not bypassed.

Your environment

• latest main branch

Aha! Link: https://nginx.aha.io/features/NKG-51

[pleshakov]

this #416 will probably fix it