Use default EA repr for IntervalArray
IntervalArray still has a custom repr:

```
In [41]: pd.arrays.IntervalArray.from_breaks(range(3))                                                                                                                          
Out[41]: 
IntervalArray([(0, 1], (1, 2]],
              closed='right',
              dtype='interval[int64]')
```

We should convert that to the default EA repr.