What happened?

When doing operations on numpy arrays and xarray variables mypy does not understand that the output is always a xarray variable regardless of the order. See example.

What did you expect to happen?

mypy to pass for the example code.

Minimal Complete Verifiable Example

```Python import numpy as np import xarray as xr

x = np.array([1, 2, 4]) v = xr.Variable(["x"], x)

numpy first:

xv = x * v xv.values # error: "ndarray[Any, dtype[bool_]]" has no attribute "values" [attr-defined] if isinstance(xv, xr.Variable): xv.values

variable first:

vx = v * x vx.values if isinstance(vx, xr.Variable): vx.values ```

MVCE confirmation

• [X] Minimal example — the example is as focused as reasonably possible to demonstrate the underlying issue in xarray.
• [X] Complete example — the example is self-contained, including all data and the text of any traceback.
• [X] Verifiable example — the example copy & pastes into an IPython prompt or Binder notebook, returning the result.
• [X] New issue — a search of GitHub Issues suggests this is not a duplicate.

Relevant log output

No response

Anything else we need to know?

Seen in #7741

Environment

xr.show_versions() INSTALLED VERSIONS ------------------ commit: None python: 3.9.16 (main, Mar 8 2023, 10:39:24) [MSC v.1916 64 bit (AMD64)] python-bits: 64 OS: Windows OS-release: 10 machine: AMD64 processor: Intel64 Family 6 Model 58 Stepping 9, GenuineIntel byteorder: little LC_ALL: None LANG: en libhdf5: 1.10.6 libnetcdf: None xarray: 2023.4.2 pandas: 2.0.0 numpy: 1.23.5 scipy: 1.10.1 netCDF4: None pydap: None h5netcdf: None h5py: 2.10.0 Nio: None zarr: None cftime: None nc_time_axis: None PseudoNetCDF: None iris: None bottleneck: None dask: 2023.4.0 distributed: 2023.4.0 matplotlib: 3.5.3 cartopy: None seaborn: 0.12.2 numbagg: None fsspec: 2023.4.0 cupy: None pint: None sparse: None flox: None numpy_groupies: None setuptools: 67.7.1 pip: 23.1.1 conda: 23.3.1 pytest: 7.3.1 mypy: 1.2.0 IPython: 8.12.0 sphinx: 6.1.3