Partial mode not raising errors

```py
import jiter

v = jiter.from_json(b'[{"a": "foo", "b": 1}, {"a": "bar": 2}, {"a": "baz", "b": 3}]', partial_mode='trailing-strings')

print(v)
```

This passes and prints `[{'a': 'foo', 'b': 1}, {'a': 'bar'}]`, it definitely shouldn't.