Bump node from 20.13-alpine to 20.15-alpine in /silta-node/20-alpine #383

	name: Test build docker images

	on:
	pull_request:

	jobs:
	changed_files:
	name: Get changed Dockerfiles
	runs-on: ubuntu-latest
	outputs:
	matrix: ${{ steps.changes.outputs.matrix}}
	steps:
	- name: Checkout repository
	uses: actions/checkout@v4
	with:
	fetch-depth: 0
	- name: Get changed Dockerfiles
	id: changes
	run: \|
	dockerfile_list_json=$(git diff --name-only --diff-filter=ACMRT \
	${{ github.event.pull_request.base.sha }} ${{ github.event.pull_request.head.sha }} \
	\| grep Dockerfile$ \
	\| jq -Rsc '. / "\n" - [""]' )
	echo "matrix=${dockerfile_list_json}" > $GITHUB_OUTPUT

	test_build:
	name: Test build
	runs-on: ubuntu-latest
	needs: changed_files
	strategy:
	fail-fast: false
	matrix:
	dockerfile: ${{ fromJson(needs.changed_files.outputs.matrix) }}
	if: ${{needs.changed_files.outputs.matrix}}
	steps:
	- name: Checkout repository
	uses: actions/checkout@v4
	- name: Building dockerfile
	run: \|
	set -ex
	tmpName="test-image-$RANDOM"
	docker build $(dirname ${{matrix.dockerfile}}) --file ${{matrix.dockerfile}} --tag $tmpName
	# Print versions
	if [[ ${{matrix.dockerfile}} == "silta-php-fpm" ]]; then
	docker run -t --rm $tmpName php -r 'echo "PHP " . PHP_VERSION;'
	fi
	if [[ ${{matrix.dockerfile}} == "silta-node" ]]; then
	docker run -t --rm $tmpName node -v
	fi

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