EventType AutoCreate: set the `specversion` and `id` fields on the eventtypes

[Cali0707]

Problem We recently moved to reconciling the v1beta3 eventtypes, but the eventtype autocreate code is still creating the v1beta2 resources. We should switch to creating v1beta3 resources and setting the specversion field to be the cloudevents spec version of the event that triggered the autocreate, as well as setting the id field on the eventtype (but with no value)

Persona: Which persona is this feature for?

Exit Criteria The eventtype autocreate feature successfully create v1beta3 eventtypes and all existing e2e tests still pass

Time Estimate (optional): How many developer-days do you think this may take to resolve? 1

Additional context (optional) Add any other context about the feature request here.

• The autocreate package is here: https://github.com/knative/eventing/blob/main/pkg/eventtype/eventtypes.go