Breaking change missing in 5 to 6 upgrade

Seems the signature of `BaseConstraint` has changed:

```
public function addError(?JsonPointer $path, $message, $constraint = '', ?array $more = null)

public function addError(ConstraintError $constraint, ?JsonPointer $path = null, array $more = []): void
```

Is that intentional? Guess the fact it isn't optional anymore is the problem there.