Test configs in batches with matrix strategy #2

	#
	# identify-and-trigger.yml
	# Identify new / updated configs in the PR
	#

	name: Identify Changed Directories

	on:
	pull_request:
	branches:
	#- import-2.1.x
	paths-ignore:
	- '*/.md'

	jobs:
	identify-dirs:

	name: Identify Changed Directories
	#if: github.repository == 'MarlinFirmware/Configurations'

	runs-on: ubuntu-latest
	outputs:
	dir_batches: ${{ steps.create-batches.outputs.batches }}
	steps:
	- name: Check out the PR
	uses: actions/checkout@v4

	- name: Get changed directories
	id: get-dirs
	run: \|
	# Get the base branch of the Pull Request
	BASE_BRANCH=$(jq -r .pull_request.base.ref <$GITHUB_EVENT_PATH)

	# Get origin for comparison
	git fetch --depth=1 origin $BASE_BRANCH

	# Use `git diff` to get a list of folders with altered .h files
	# between the current commit and the base branch of the Pull Request
	DIRS=$(git diff --name-only --diff-filter=AMR origin/$BASE_BRANCH HEAD \| grep -E ".+\.h" \| while IFS= read -r f; do dirname "$f"; done \| uniq)

	# Exit if nothing testable changed
	[[ -z $DIRS ]] && { echo "No Configuration changes detected."; exit ; }

	# Set DIRS in the persistent environment
	echo "$DIRS" > changed_dirs.txt

	- name: Create batches
	id: create-batches
	run: \|
	# Must be <256 jobs per workflow
	BATCH_SIZE=100
	DIRS=$(cat changed_dirs.txt)
	BATCHES=$(echo "$DIRS" \| xargs -n$BATCH_SIZE \| jq -R -s -c 'split("\n") \| map(select(length > 0))')
	echo "::set-output name=batches::$BATCHES"

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