Add PHP_CS_FIXER_FUTURE_MODE

Author: kubawerlos

.github/workflows/ci.yaml

@@ -126,6 +126,8 @@ jobs:
       - run: composer update --no-progress --classmap-authoritative ${{ matrix.composer-flags }}
 
       - if: matrix.install-phpunit-12
+        env:
+          PHP_CS_FIXER_FUTURE_MODE: 1
         run: ./vendor/bin/php-cs-fixer fix --quiet --rules=php_unit_attributes
 
       - run: composer show | grep php-cs-fixer