CI: mypy error in pandas/core/indexes/datetimelike.py::_simple_new
Seeing this in a bunch of unrelated PRs (my own and others'):
```
pandas/core/indexes/datetimelike.py:776: error: Argument 1 to "_simple_new" of "DatetimeIndexOpsMixin" has incompatible type "Union[ExtensionArray, Any]"; expected "Union[DatetimeArray, TimedeltaArray, PeriodArray]"  [arg-type]
Found 1 error in 1 file (checked 1119 source files)
Performing static analysis using mypy DONE
```
I wonder if it's a bug on master?