Merge pull request #6 from mmachatschek/test_php8.1

Test PHP 8.1

Author: mmachatschek

.github/workflows/tests.yml

@@ -17,7 +17,7 @@ jobs:
             -   name: Install PHP
                 uses: shivammathur/setup-php@v2
                 with:
-                    php-version: 8.0
+                    php-version: 8.1
             -   name: Install dependencies
                 run: composer update --prefer-dist --no-progress
             -   name: Run types tests with PHPStan
@@ -28,7 +28,7 @@ jobs:
         strategy:
             fail-fast: false
             matrix:
-                php: ['8.0']
+                php: ['8.0', '8.1']
                 stability: [prefer-lowest, prefer-stable]
 
         name: PHP ${{ matrix.php }} - ${{ matrix.stability }}