Build on latest Java, test through lowest possible - approach 2 #654

	name: Java cross-version tests

	on:
	push:
	branches:
	- master
	- "szpak/**"
	- "marc/**"
	pull_request:
	branches:
	- '*'
	merge_group:

	jobs:
	openjdk:
	strategy:
	matrix:
	# TODO: Add 19+
	jdk: [11, 17]
	testJdk: [auto, 8]
	name: "OpenJDK ${{ matrix.jdk }} (with testJDK ${{ matrix.testJdk }})"
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v4
	- uses: actions/setup-java@v4
	with:
	java-version: ${{ matrix.jdk }}
	distribution: 'zulu'
	- uses: gradle/gradle-build-action@v2
	# Workaround https://github.com/ajoberstar/gradle-stutter/issues/22
	- name: Reduce number of Gradle regressions builds
	run: \|
	# Keep only the last Gradle version per Stutter matrix; for each line this transformation is done:
	# java11=6.2.2,6.9.4,7.0.2,7.6.1,8.0.2,8.1.1,8.2-rc-1
	# ->
	# java11=8.2-rc-1
	# The trick is that \3 will greedily eat everything before the last comma.
	sed -r 's/^(.?)=(.?),(.),(.?)$/\1=\2,\4/g' -i stutter.lockfile
	cat stutter.lockfile
	- name: Test cross Java versions compatibility
	run: \|
	./gradlew --version
	./gradlew -q javaToolchains
	./gradlew --stacktrace -PnexusPublishPlugin.test.java=${{ matrix.testJdk }} build compatTestJava${{ matrix.jdk }}

Provide feedback