pingsource-controller cannot update pingsources/status

[lionelvillard]

Describe the bug
seeing this in the log:

Warning  UpdateFailed          44s (x5 over 44s)  pingsource-controller  Failed to update status for "pinger": pingsources.sources.knative.dev "pinger" is forbidden: User "system:serviceaccount:knative-eventing:pingsource-mt-adapter" cannot update resource "pingsources/status" in API group "sources.knative.dev" in the namespace "test"

Expected behavior
no error

To Reproduce
Steps to reproduce the behavior.

Knative release version

Additional context
Add any other context about the problem here such as proposed priority

[lionelvillard]

The pingsource-mt-adapter should not update the status. The generated reconciler should be configured as such.

[grantr]

We might need to make this change in other adapters using gen-reconciler as well.