drop test-infra code #2411

Job	Run time
Unit Test (knative/serving)	9m 58s
Unit Test (knative/networking)	4m 3s
Unit Test (knative/eventing)	13m 53s
Unit Test (knative/operator)	7m 1s
Unit Test (knative/client)	7m 14s
Unit Test (knative-extensions/eventing-autoscaler-keda)	4m 50s
Unit Test (knative-extensions/eventing-ceph)	52s
Unit Test (knative-extensions/eventing-github)	5m 29s
Unit Test (knative-extensions/eventing-gitlab)	5m 2s
Unit Test (knative-extensions/eventing-kafka-broker)	1m 7s
Unit Test (knative-extensions/eventing-rabbitmq)	56s
Unit Test (knative-extensions/eventing-redis)	5m 52s
Unit Test (knative-extensions/kn-plugin-admin)	4m 44s
Unit Test (knative-extensions/net-certmanager)	4m 28s
Unit Test (knative-extensions/net-contour)	5m 3s
Unit Test (knative-extensions/net-istio)	5m 56s
Unit Test (knative-extensions/net-kourier)	4m 51s
	1h 31m 19s

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