Adapt NetworkPolicys according to recent refactorings

[ScheererJ]

How to categorize this PR?

/area dev-productivity ops-productivity networking security
/kind enhancement

What this PR does / why we need it:
This PR adapts the NetworkPolicys according to the recent refactorings in gardener/gardener
See also gardener/gardener#7589 and https://github.com/gardener/gardener/blob/master/docs/concepts/resource-manager.md#networkpolicy-controller.

Which issue(s) this PR fixes:
Part of gardener/gardener#7352

Special notes for your reviewer:
/cc @rfranzke @oliver-goetz @timuthy

Depends on gardener/gardener@v1.66 to create the expected network policies in the extension namespace.

Release note:

Adapted extension components to support the [FullNetworkPoliciesInRuntimeCluster](https://github.com/gardener/gardener/blob/master/docs/deployment/feature_gates.md#list-of-feature-gates) feature gate introduced by `gardener/gardener` v1.66, see [here](https://github.com/gardener/gardener/blob/master/docs/concepts/resource-manager.md#networkpolicy-controller) and [#7352](https://github.com/gardener/gardener/pull/7589) for more information.

[gardener-robot]

@ScheererJ Thank you for your contribution.

[DockToFuture]

I guess we need here to also set the metrics port on the svc.

[ScheererJ]

I guess we need here to also set the metrics port on the svc.

We could also explicitly define the metrics port in the service. However, also other extensions do not specify the metrics port, e.g. gardener/gardener-extension-provider-aws@f028217. For extensions with a webhook usually that port is explicitly exposed.

Do you want to also expose the metrics port (unlike some other extensions)?

[DockToFuture]

I guess we need here to also set the metrics port on the svc.

We could also explicitly define the metrics port in the service. However, also other extensions do not specify the metrics port, e.g. gardener/gardener-extension-provider-aws@f028217. For extensions with a webhook usually that port is explicitly exposed.

Do you want to also expose the metrics port (unlike some other extensions)?

I looked at the calico extension and there we have explicitly exposed the port. It looked like there was something missing.

[rfranzke]

/lgtm