Missing `EARTH_RADIUS` in mapping satellite's geodetic coordinates to cartesian coordinates while doing parallax correction

Describe the bug

Mapping geodetic coordinate to cartesian coordinates should use radial distance.

For a satellite, its radial distance is EARTH_RADIUS + satellite_altitude instead of satellite_altitude.

To Reproduce

Copy codes from

https://github.com/pytroll/satpy/blob/687494c6887f54b1991fe8accf1c071307b542ad/satpy/modifiers/parallax.py#L158

I have codes below.

import numpy as np
from satpy.modifiers.parallax import EARTH_RADIUS
from satpy.utils import lonlat2xyz

sat_lon = 0
sat_lat = 90.
sat_alt = EARTH_RADIUS * 1e3  # satellite altitude in meters, equal to Earth radius
lon = 0  # cloud longitude
lat = 90  # cloud latitude

sat_xyz = np.hstack(lonlat2xyz(sat_lon, sat_lat)) * sat_alt
cth_xyz = np.stack(lonlat2xyz(lon, lat), axis=-1) * EARTH_RADIUS * 1e3  # km → m

assert not np.all(sat_xyz == cth_xyz)  # sat_xyz must not equals cth_xyz in this scenario

Expected behavior
Passed assert not np.all(sat_xyz == cth_xyz).

Actual results
AssertionError

Screenshots
Omitted.

Environment Info:
Omitted.

Additional context

# I think the fix must be like
sat_xyz = np.hstack(lonlat2xyz(sat_lon, sat_lat)) * (sat_alt + EARTH_RADIUS * 1e3)  # EARTH_RADIUS km → m 

Well, the fix is simple, should I make a PR/MR?