Update net-istio nightly (#12519)
Update net-istio nightly (#12519)

bumping knative.dev/net-istio 2ab0b98...957190f:
  > 957190f Update community files (# 844)

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