Set a high terminationGracePeriodSeconds on webhook (#8640)
Set a high terminationGracePeriodSeconds on webhook (#8640)

When our webhook drains, it sleeps for `network.DefaultDrainTimeout` after failing readiness probes before exiting, see [here](https://github.com/knative/pkg/blob/4419e613c133505ea5109380102765a7699b9bf8/webhook/webhook.go#L229-L234) which is configured to [this value](https://github.com/knative/pkg/blob/4419e613c133505ea5109380102765a7699b9bf8/network/network.go#L39-L43).

I suspect that the default `terminationGracePeriodSeconds` (of `30`) is clipping this sleep already (due to the coordination involved), but I am also thinking about raising this value due to seeing a non-zero number of EOF messages running chaos during our e2e testing.
knative/serving,knative/serving