Update net-istio nightly (#10889)
Update net-istio nightly (#10889)

bumping knative.dev/net-istio fe7d984...6ef3289:
  > 6ef3289 upgrade to latest dependencies (# 534)

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