Update actions/checkout action to v6 #4503

	name: Verify

	on: [push, pull_request]

	jobs:
	build:
	runs-on: ubuntu-latest
	name: Gradle build

	steps:
	- uses: actions/checkout@v6
	- name: Set up JDK 21
	uses: actions/setup-java@v5
	with:
	distribution: temurin
	java-version: 21
	- uses: gradle/actions/wrapper-validation@v5
	- name: Build with Gradle
	run: ./gradlew --build-cache build -x test -x spotlessCheck
	- name: Check license
	run: ./gradlew spotlessCheck
	- name: Test with Gradle
	run: ./gradlew test --info

	build-docker:
	runs-on: ubuntu-latest
	name: Docker build

	steps:
	- uses: actions/checkout@v6
	- name: Build as Docker image
	run: docker build . -f docker/Dockerfile

	enforce-encoding:
	runs-on: ubuntu-latest
	name: Encoding check

	steps:
	- uses: actions/checkout@v6
	- name: Remove allowed us-ascii files before check
	run: rm src/main/resources/locale.properties src/main/resources/locale_en_US.properties # This needs improvement
	- name: Check UTF-8 for resource bundles
	run: \|
	find src/main/resources/locale* -type f -exec file --mime {} \; \| grep -v charset=utf-8 && NOT_UTF_FOUND=1 \|\| true
	[[ \"$NOT_UTF_FOUND\" == \"1\" ]] && exit 1 \|\| true

	verify-docs:
	runs-on: ubuntu-latest
	name: Docs build

	steps:
	- uses: actions/checkout@v6
	- uses: actions/setup-python@v6
	with:
	python-version: 3.14
	- run: pip install pipenv && pipenv install && pipenv run mkdocs build

Provide feedback