QST: Should list-likes with pd.NA have an inferred nullable dtype if possible?
It looks like in each of these cases the dtype is inferred as object, but does it make sense to try to use a nullable extension type when possible?
```python
[ins] In [1]: pd.Series([1, 2, pd.NA]).dtype                                                                                                                                                                 
Out[1]: dtype('O')

[ins] In [2]: pd.Series([True, False, pd.NA]).dtype                                                                                                                                                          
Out[2]: dtype('O')

[ins] In [3]: pd.Series(["a", "b", pd.NA]).dtype                                                                                                                                                             
Out[3]: dtype('O')
```
