Add phpstan level 7(#544)

.github/workflows/code-quality.yml

@@ -0,0 +1,42 @@
+name: code-quality
+
+on:
+  push:
+    branches:
+      - 2.x
+  pull_request:
+    branches:
+      - 2.x
+
+jobs:
+  tests:
+    runs-on: ubuntu-22.04
+
+    strategy:
+      fail-fast: true
+      matrix:
+        php: [ 8.2 ]
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php }}
+
+      - name: Cache Composer packages
+        id: composer-cache
+        uses: actions/cache@v4
+        with:
+          path: vendor
+          key: ${{ runner.os }}-php-${{ hashFiles('**/composer.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-php-
+
+      - name: Install dependencies
+        if: steps.composer-cache.outputs.cache-hit != 'true'
+        run: composer install --prefer-dist --no-progress --no-suggest
+
+      - name: Run PHPStan
+        run: ./vendor/bin/phpstan analyse