BUG: constructing DTA/TDA from xarray/dask/pandasarray
- [x] closes #24539
- [x] closes #24615
- [x] tests added / passed
- [x] Ensure all linting tests pass, see [here](https://pandas.pydata.org/pandas-docs/dev/development/contributing.html#code-standards) for how to run them
- [ ] whatsnew entry

lgtm, is this user facing at all? or *only* library facing? e.g. seems now can construct ```pd.to_datetime(pd.Series(...., dtype='Int64')))``` might work now? > e.g. seems now can construct pd.to_datetime(pd.Series(...., dtype='Int64'))) might work now?

this works on master.

> is this user facing at all? or only library facing?

AFAICT only library-facing. looks like a mypy complaint crept in.  updated #40361 to fix it