Issue #3299678 by mondrake, catch, longwave: Deprecate DiffEngine and replace with sebastian/diff

Author: longwave

composer.json

@@ -30,6 +30,7 @@
 "psr/http-message": "~1.0.1",
 "psr/log": "~3.0.0",
 "ralouphie/getallheaders": "~3.0.3",
+"sebastian/diff": "~4.0.4",
 "symfony/console": "~v6.2.5",
 "symfony/dependency-injection": "~v6.2.6",
 "symfony/deprecation-contracts": "~v3.2.0",