[Automated] Update backstage-plugins-eventing nightly (#119)

Update eventing nightly

bumping knative.dev/eventing f53d038...9d67389:
  > 9d67389 [chore] Do not generate SSL env vars for each struct entry, just once per containersource/image (# 8315)
  > 35d8c63 [chore] Use a generic access/secret key in the secret for AWS connections (# 8312)

Signed-off-by: Knative Automation <[email protected]>

Author: knative-automation