Vendorless presubmit-test script

Author: cardil

test/presubmit-tests.sh

@@ -24,9 +24,9 @@
 # Markdown linting failures don't show up properly in Gubernator resulting
 # in a net-negative contributor experience.
 export DISABLE_MD_LINTING=1
-export GO111MODULE=on
 
-source $(dirname $0)/../vendor/knative.dev/hack/presubmit-tests.sh
+# shellcheck disable=SC1090
+source "$(go run knative.dev/hack/cmd/script presubmit-tests.sh)"
 
 # TODO(mattmoor): integration tests