Don't rely on the existence of vendor dir at root level

[cardil]

net-istio/third_party/library.sh

Line 17 in d5104e5

source "$(git rev-parse --show-toplevel)/vendor/knative.dev/hack/library.sh"

This breaks knative/client#1953 integration test: https://prow.knative.dev/view/gs/knative-prow/pr-logs/pull/knative_client/1953/integration-tests_client_main/1814032077515919360#1:build-log.txt%3A6886

Instead, use hack script embedding:

# shellcheck disable=SC1090
source "$(go run knative.dev/hack/cmd/script library.sh)"

/kind bug

[skonto]

I think this is the current convention in Knative see for example: https://github.com/knative-extensions/sample-controller/blob/main/hack/tools.go#L25. By trying to move to a vendorless setup and by using the knative.dev/hack/cmd/script in that client PR it is kind of expected things to break. So I feel this is part of the work that needs to be done because of the migration process: https://github.com/knative/hack/tree/main/cmd/script#migration-to-a-vendorless-project. Is this kind of a strict requirement for all knative repos (lacking context here)? cc @dprotaso
I am trying to understand if we just need to fix this part because client uses it in e2e (client is becoming vendorless) or we should be moving this repo (others too).

[cardil]

Moving to vendorless setup isn't mandatory, but it's recommended going forward. For reasons of that effort, please see
knative/infra#134 description.