[Go] time64[ns] values aren't bound correctly

```
-{'res': NaiveTime(hour=13, minute=45, second=31, nanosecond=123456000)}
-{'res': NaiveTime(hour=12, minute=30, second=45, nanosecond=500000000)}
+{'res': NaiveTime(hour=6, minute=38, second=43, nanosecond=456789000)}
+{'res': NaiveTime(hour=8, minute=38, second=20, nanosecond=0)}
```

The top value is 49531123456 nanoseconds, so I'm not sure where the 789 is coming from.