Run tests with PHP 8.1

Author: lochmueller

.github/workflows/test.yml

@@ -8,7 +8,7 @@ jobs:
       - name: Setup PHP with PECL extension
         uses: shivammathur/setup-php@v2
         with:
-          php-version: '8.0'
+          php-version: '8.1'
           extensions: imagick
       - name: Composer install
         run: composer install --optimize-autoloader --prefer-dist