Replace JDK 18 build with 21 #138

	name: CI

	on:
	push:
	branches:
	- main
	pull_request:
	branches:
	- '*'

	permissions:
	contents: read # to fetch code (actions/checkout)

	jobs:

	build-and-verify:
	name: Build and verify (JDK ${{ matrix.java }})
	runs-on: ubuntu-latest
	strategy:
	fail-fast: false
	matrix:
	java: ['8', '11', '17', '21']
	steps:
	- uses: actions/checkout@v2
	- name: Download Maven # Download with default JDK because OpenJDK 6 does not support TLS 1.2
	run: ./mvnw --version
	- name: Set up JDK 6
	if: ${{ matrix.java == '6'}}
	uses: actions/setup-java@v1
	with:
	java-version: ${{ matrix.java }}
	- name: Set up JDK
	if: ${{ matrix.java != '6'}}
	uses: actions/setup-java@v2
	with:
	java-version: ${{ matrix.java }}
	distribution: temurin
	cache: maven
	- name: Build and verify
	run: ./mvnw verify javadoc:javadoc site:site --batch-mode --errors --settings .github/workflows/settings.xml

	publish-snapshots:
	name: Publish snapshot artifacts
	if: github.event_name == 'push' && github.repository == 'junit-team/junit4' && github.ref == 'refs/heads/main'
	needs: build-and-verify
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v2
	- name: Download Maven # Download with default JDK because OpenJDK 6 does not support TLS 1.2
	run: ./mvnw --version
	- name: Set up JDK
	uses: actions/setup-java@v1
	with:
	java-version: 8
	- name: Publish snapshot artifacts
	env:
	OSSRH_USERNAME: ${{ secrets.OSSRH_USERNAME }}
	OSSRH_PASSWORD: ${{ secrets.OSSRH_PASSWORD }}
	run: ./mvnw deploy --batch-mode --errors --activate-profiles generate-docs --settings .github/workflows/settings.xml

Provide feedback