ci: add rector refactoring workflow

.github/CONTRIBUTING.md

@@ -171,6 +171,7 @@ Our project employs [GitHub Actions](https://github.com/features/actions) for co
 | [`coding-standards.yml`](workflows/coding-standards.yml)       | Checks `yaml`, `md`, `composer`, `php` and commit coding standards. |
 | [`create-release.yml`](workflows/create-release.yml)           | Creates a release on GitHub.                                        |
 | [`dependency-analysis.yml`](workflows/dependency-analysis.yml) | Checks for dependency issues.                                       |
+| [`refactoring.yml`](workflows/refactoring.yml)                 | Runs rector/rector code check.                                      |
 | [`security-analysis.yml`](workflows/security-analysis.yml)     | Checks for security issues.                                         |
 | [`shellcheck.yml`](workflows/shellcheck.yml)                   | Checks shell scripts.                                               |
 | [`static-analysis.yml`](workflows/static-analysis.yml)         | Runs `psalm` and `phpstan` tools.                                   |

.github/workflows/refactoring.yml

@@ -0,0 +1,65 @@
+---
+
+on:  # yamllint disable-line rule:truthy
+  pull_request:
+    branches:
+      - master
+    paths:
+      - 'src/**'
+      - 'tests/**'
+      - '.php-cs-fixer.dist.php'
+      - 'rector.php'
+
+name: ⚙️ Refactoring
+
+jobs:
+  refactoring:
+    timeout-minutes: 4
+    runs-on: ${{ matrix.os }}
+    concurrency:
+      cancel-in-progress: true
+      group: refactoring-${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+    strategy:
+      fail-fast: true
+      matrix:
+        os:
+          - ubuntu-latest
+        php-version:
+          - '8.1'
+        dependencies:
+          - locked
+    steps:
+      - name: 📦 Check out the codebase
+        uses: actions/[email protected]
+
+      - name: 🛠️ Setup PHP
+        uses: shivammathur/[email protected]
+        with:
+          php-version: ${{ matrix.php-version }}
+          extensions: mbstring
+          ini-values: error_reporting=E_ALL
+          coverage: none
+
+      - name: 🛠️ Setup problem matchers
+        run: echo "::add-matcher::${{ runner.tool_cache }}/php.json"
+
+      - name: 🤖 Validate composer.json and composer.lock
+        run: composer validate --ansi --strict
+
+      - name: 🔍 Get composer cache directory
+        uses: wayofdev/gh-actions/actions/composer/[email protected]
+
+      - name: ♻️ Restore cached dependencies installed with composer
+        uses: actions/[email protected]
+        with:
+          path: ${{ env.COMPOSER_CACHE_DIR }}
+          key: php-${{ matrix.php-version }}-composer-${{ matrix.dependencies }}-${{ hashFiles('composer.lock') }}
+          restore-keys: php-${{ matrix.php-version }}-composer-${{ matrix.dependencies }}-
+
+      - name: 📥 Install "${{ matrix.dependencies }}" dependencies
+        uses: wayofdev/gh-actions/actions/composer/[email protected]
+        with:
+          dependencies: ${{ matrix.dependencies }}
+
+      - name: ⚙️ Run automated refactoring with rector/rector
+        run: composer refactor:ci