Remove third_party directory

[dibyom]

Changes

The third_party directory contains source code of some of our third_party dependencies that need to be distributed with the built images as required by their licenses. However, our publish-triggers-release task [1] already includes the source code of all of our dependencies in the image rendering the separate third_party directory redundant.

This is a port of tektoncd/pipeline#6416

[1]

triggers/tekton/publish.yaml

Lines 104 to 117 in 2713832

	# For each cmd/* directory, include a full gzipped tar of all source in
	# vendor/. This is overkill. Some deps' licenses require the source to be
	# included in the container image when they're used as a dependency.
	# Rather than trying to determine which deps have this requirement (an(params.imageRegistryd
	# probably get it wrong), we'll just targz up the whole vendor tree and
	# include it. As of 9/20/2019, this amounts to about 11MB of additional
	# data in each image.
	TMPDIR=$(mktemp -d)
	tar cfz ${TMPDIR}/source.tar.gz vendor/
	for d in cmd/*; do
	if [ -d ${d}/kodata/ ]; then
	ln -s ${TMPDIR}/source.tar.gz ${d}/kodata/
	fi
	done

Submitter Checklist

These are the criteria that every PR should meet, please check them off as you
review them:

• Includes tests (if functionality changed/added)
• Includes docs (if user facing)
• Commit messages follow commit message best practices
• Release notes block has been filled in or deleted (only if no user facing changes)

See the contribution guide for more details.

Release Notes

/kind misc

[khrm]

/lgtm

[khrm]

/test pull-tekton-triggers-build-tests

[dibyom]

/assign @savitaashture

[dibyom]

/retest

[khrm]

/lgtm

[khrm]

/approve

[tekton-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: khrm

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 [khrm]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment