Docs: fix cert-manager manual deploy guide in `DEVELOPMENT.md`. #6893

Job	Run time
Unit Test (eventing-autoscaler-keda, knative-extensions)	5m 43s
Unit Test (eventing-github, knative-extensions)	6m 14s
Unit Test (eventing-gitlab, knative-extensions)	5m 52s
Unit Test (eventing-ceph, knative-extensions)	5m 34s
Unit Test (eventing-rabbitmq, knative-extensions)	7m 38s
Unit Test (eventing-kafka-broker, knative-extensions)	10m 5s
	41m 6s

Provide feedback