Update net-kourier nightly (#11504)
Update net-kourier nightly (#11504)

bumping knative.dev/net-kourier 1537e84...af89ab8:
  > af89ab8 upgrade to latest dependencies (# 546)
  > 1e08b85 upgrade to latest dependencies (# 545)
  > 8d115ed upgrade to latest dependencies (# 544)

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