Support exposing the Audience of a Channel

[creydr]

As the Eventing OIDC feature track describes, Addressables (and thus Channels) need to announce their audience in .status.address.audience in the format GROUP/KIND/NAMESPACE/NAME (e.g. messaging.knative.dev/channel/myns/mychannel).

In particular the channel controller should:

• when the feature flag (see Add authentication.oidc feature flag #7174) is disabled:
  • no change in behavior
• when the feature flag (see Add authentication.oidc feature flag #7174) is enabled:
  • Set the Channels .status.address.audience accordingly.

Additional Information:

• Requires Add Audience field in duckv1.Addressable pkg#2795
• Requires Add Audience field in CRDs #7189

[vishal-chdhry]

/assign

[vishal-chdhry]

I think the address should be set then from the IMC controller with the correct audience. Because when we set it in the channel reconciler, it will overwrite the value set from the IMC (or vice versa).

/cc @pierDipi @creydr