Refactor GitHub Actions workflow for PHP tests

Simplified and streamlined the CI workflow, merging jobs and renaming the workflow file to `test.yml`. Improved test matrix to include multiple OS and PHP versions with dependency variations. Added caching for Composer dependencies to enhance performance.

.github/workflows/test.yml

@@ -0,0 +1,45 @@
+name: Tests
+
+on: ['push', 'pull_request']
+
+jobs:
+  ci:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: true
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+        php: ['8.2', '8.3', '8.4']
+        dependency-version: [prefer-lowest, prefer-stable]
+
+    name: Tests PHP${{ matrix.php }} - ${{ matrix.os }} - ${{ matrix.dependency-version }}
+
+    steps:
+
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php }}
+          extensions: dom, mbstring, zip
+          coverage: xdebug
+
+      - name: Get Composer cache directory
+        id: composer-cache
+        shell: bash
+        run: echo "dir=$(composer config cache-files-dir)" >> $GITHUB_OUTPUT
+
+      - name: Cache dependencies
+        uses: actions/cache@v3
+        with:
+          path: ${{ steps.composer-cache.outputs.dir }}
+          key: dependencies-php-${{ matrix.php }}-os-${{ matrix.os }}-version-${{ matrix.dependency-version }}-composer-${{ hashFiles('composer.json') }}
+          restore-keys: dependencies-php-${{ matrix.php }}-os-${{ matrix.os }}-version-${{ matrix.dependency-version }}-composer-
+
+      - name: Install Composer dependencies
+        run: composer update --${{ matrix.dependency-version }} --no-interaction --prefer-dist
+
+      - name: Integration Tests
+        run: php ./vendor/phpunit/phpunit/phpunit --testsuite default