TYP: remove mypy ignore from pandas/core/construction.py
Related to #37715
mypy ignore[assignment] was removed from pandas/core/construction.py
Looks like mypy raises an error, I will fix it. I think the issue might be that `astype` isn't meant to be called on `numpy.ma.MaskedArray` https://numpy.org/doc/stable/reference/routines.ma.html

Calling it, the return type is typed to be `ndarray`, even though if we print it we see it's `numpy.ma.MaskedArray`:
```python
data = np.ma.MaskedArray([1,2,3], mask=[False, False, True])
reveal_type(data)  # Revealed type is "numpy.ma.core.MaskedArray[Any, Any]"
reveal_type(data.astype('int64', copy=True))  # Revealed type is "numpy.ndarray[Any, numpy.dtype[Any]]"
```
Might be worth checking if there's an issue in numpy about it, and if not, then reporting to them? Perhaps this could be made more precise on their end?

The method which says "Convert the input to a masked array of the given data-type" is the one you'd originally used: `numpy.ma.asarray`, so your original solution was probably the correct one, sorry for the noise 🙈 The docs say it that `asarray` doesn't copy if the original data is an ndarray anyway > I think the issue might be that `astype` isn't meant to be called on `numpy.ma.MaskedArray` https://numpy.org/doc/stable/reference/routines.ma.html
> 
> Calling it, the return type is typed to be `ndarray`, even though if we print it we see it's `numpy.ma.MaskedArray`:
> 
> ```python
> data = np.ma.MaskedArray([1,2,3], mask=[False, False, True])
> reveal_type(data)  # Revealed type is "numpy.ma.core.MaskedArray[Any, Any]"
> reveal_type(data.astype('int64', copy=True))  # Revealed type is "numpy.ndarray[Any, numpy.dtype[Any]]"
> ```
> 
> Might be worth checking if there's an issue in numpy about it, and if not, then reporting to them? Perhaps this could be made more precise on their end?

Thanks, I'll check if there's an issue on GitHub about it.
> 
> The method which says "Convert the input to a masked array of the given data-type" is the one you'd originally used: `numpy.ma.asarray`, so your original solution was probably the correct one, sorry for the noise 🙈 The docs say it that `asarray` doesn't copy if the original data is an ndarray anyway

I rolled back the commit to the first one.
