Update net-kourier nightly (#11912)
Update net-kourier nightly (#11912)

bumping knative.dev/net-kourier 8b94798...289da39:
  > 289da39 drop scheduled actions (# 625)
  > 7a4dfd3 upgrade to latest dependencies (# 624)

Signed-off-by: Knative Automation <f415700d4d0ce1c81810fe7553e3eea2bed16231@knative.team>
knative/serving,knative/serving