Negative pixel size if area is flipped

Code Sample, a minimal, complete, and verifiable piece of code

from pyresample.geometry import AreaDefinition

area_def = AreaDefinition(
    "test",
    "test",
    "test",
    projection={"proj": "geos", "lon_0": 0, "h": 35785831.0},
    width=2,
    height=2,
    area_extent=[1, 1, -1, -1]   # flipped, upper right corner is S-E
)
area_def.pixel_size_x

Problem description

The pixel_size_x/y attribute of a flipped area is negative.

Expected Output

1.0

Actual Result, Traceback if applicable

-1.0

Versions of Python, package at hand and relevant dependencies

pyresample-1.22.3