Introduce `workshop` module and configure integration-test #3

	# If requested by means of a pull request comment, runs integration tests
	# against the project, using the code found on the pull request branch.
	# XXX: Generalize this to a matrix build of multiple integration tests,
	# possibly using multiple JDK or OS versions.
	# XXX: Investigate whether the comment can specify which integration tests run
	# run. See this example of a dynamic build matrix:
	# https://docs.github.com/en/actions/learn-github-actions/expressions#example-returning-a-json-object
	name: "Integration tests"
	on:
	issue_comment:
	types: [ created ]
	pull_request:
	push:
	permissions:
	contents: read
	jobs:
	run-integration-tests:
	name: On-demand integration test
	runs-on: ubuntu-22.04
	steps:
	- name: Check out code
	uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
	with:
	persist-credentials: false
	- name: Set up JDK
	uses: actions/setup-java@0ab4596768b603586c0de567f2430c30f5b0d2b0 # v3.13.0
	with:
	java-version: 17.0.8
	distribution: temurin
	cache: maven
	- name: Install project to local Maven repository
	run: mvn -T1C install -DskipTests -Dverification.skip
	- name: Run integration test
	run: xvfb-run ./integration-tests/checkstyle-10.12.4.sh "${{ runner.temp }}/artifacts"
	- name: Upload artifacts on failure
	if: ${{ failure() }}
	uses: actions/upload-artifact@a8a3f3ad30e3422c9c7b888a15615d19a852ae32 # v3.1.3
	with:
	name: integration-test-checkstyle-10.12.4
	path: "${{ runner.temp }}/artifacts"
	- name: Remove installed project artifacts
	run: mvn build-helper:remove-project-artifact

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