Extract tools to knative/toolbox repo

[cardil]

Which issue(s) this PR fixes:
Related to https://github.com/knative/community/issues/1291 Requires https://github.com/knative/toolbox/pull/3

[knative-prow[bot]]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: cardil

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files: - ~~[OWNERS](https://github.com/knative/test-infra/blob/main/OWNERS)~~ [cardil] Approvers can indicate their approval by writing `/approve` in a comment Approvers can cancel approval by writing `/approve cancel` in a comment

[cardil]

As https://github.com/knative/toolbox/pull/3 is now merged, the image tests should now work:

/test pull-knative-test-infra-prow-tests-image-build

[cardil]

/hold

Because we use @latest for those tools, we can't just move them. Old releases will not compile.

[krsna-m]

/reteset @cardil this might need to be broken down into smaller commits/PR to get it passing

[krsna-m]

/retest

[krsna-m]

/hold as per productivity wg meeting. We should probably stick with the old idea of keeping test-infra and archiving it so we don't have to backport this to all the older releases.

[knative-prow-robot]

PR needs rebase.

Instructions for interacting with me using PR comments are available [here](https://git.k8s.io/community/contributors/guide/pull-requests.md). If you have questions or suggestions related to my behavior, please file an issue against the [kubernetes/test-infra](https://github.com/kubernetes/test-infra/issues/new?title=Prow%20issue:) repository.

[krsna-m]

Closing because of reasons above