[Feature Request/Documentation] Support for GCP Managed Kafka with OAuth2 Authentication in Knative Kafka Broker

[naveengogu]

Summary
I'm trying to use Knative Kafka Broker with GCP Managed Kafka, which requires OAuth2 token-based authentication via SASL/PLAIN. The current documentation doesn't provide clear guidance on how to configure brokers for managed Kafka services that use short-lived OAuth tokens instead of static credentials.
Environment

Knative Eventing Version: 1.20.1
Knative Kafka Broker Version: 1.20.1
Kafka Provider: GCP Managed Kafka (Google Cloud)
Authentication Method: SASL/PLAIN with OAuth2 access tokens

Give me sample configmap for broker to access kafka cluster

issue:

k get broker
NAME                     URL   AGE     READY   REASON
poc-test-broker                96s     False   cannot obtain Kafka cluster admin, kafka: client has run out of available brokers to talk to: unexpected EOF

[naveengogu]

@creydr I went through a similar issue earlier #8593 (comment)
As per HIPAA compliance, I should not create keys for the GCP service account.
Could you please provide the steps to proceed using Workload Identity instead?