If you look at the source file you can see they have added a note
Since PHP 7 adds "object" as a reserved keyword, we can no longer have
a class * named that and retain PHP 7 compatibility. The original
class has been * renamed to "Instance", and this class is now an
extension of it. It raises an * E_USER_DEPRECATED to warn users to
So as advised, use Zend\Form\Annotation\Instance instead of Zend\Form\Annotation\Object
from PHP 7.2+ onwards the ClassName will not be allowed to be named after
special / reserverd keywords like Object.
So either you need to upgrade your Magento version which is compatible with PHP 7.2+ (Yah sounds terrible) or downgrade your PHP version.
Good news, you are not alone, there are people out there facing this issue and this one can fix your issue. (Hope it will)