$enabled static properties were removed from PHPUnit\Framework\Error\Notice and PHPUnit\Framework\Error\Warning classes since PHPUnit 8.3.0 https://github.com/sebastianbergmann/phpunit/commit/db1dce395c1843f095319a4d9652c2853ea785df

Using them in tests causes errors like Error: Access to undeclared static property PHPUnit\Framework\Error\Warning::$enabled.