Run cs-fixer action on PHP 8.1

Author: ksassnowski

.github/workflows/fix-style.yml

@@ -19,7 +19,7 @@ jobs:
       - name: Setup PHP
         uses: shivammathur/setup-php@v2
         with:
-          php-version: 8.0
+          php-version: 8.1
 
       - name: Install dependencies
         run: composer install