Adding Checkstyle linter #14

	name: Code Quality Check

	on:
	push:
	branches:
	- "master"
	- "*-rc"
	pull_request:
	types: [opened, reopened, synchronize]
	branches:
	- "**"

	jobs:
	checkstyle-and-spotless:
	runs-on: ubuntu-latest
	steps:
	- name: Checkout branch
	uses: actions/checkout@v4
	with:
	ref: ${{ github.head_ref }} # Checkout the branch of the pull request
	fetch-depth: 0

	- name: List Changed Files
	run: \|
	echo "Current branch: ${{ github.head_ref }}"
	echo "Changed files:"
	git diff --name-only origin/${{ github.base_ref }}...${{ github.head_ref }}


	- name: Setup Java & Gradle
	uses: actions/setup-java@v4
	with:
	java-version: '17'
	distribution: 'temurin'
	cache: 'gradle'

	- uses: actions/cache@v4
	name: Cache Gradle Wrapper
	id: cache-gradle-wrapper
	with:
	path: \|
	gradle/wrapper/gradle-wrapper.jar
	key: gradle-wrapper-v1

	- name: Get Gradle wrapper
	if: steps.cache-gradle-wrapper.outputs.cache-hit != 'true'
	run: \|
	./configure.sh

	- name: Run Checkstyle
	run: \|
	./gradlew clean rskj-core:checkstyleMain checkstyleTest --info

	- name: Run Spotless Check
	run: \|
	./gradlew clean rskj-core:spotlessCheck --info

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