test(test_main.py): improve mean speed test with parametrization

tests/test_main.py

@@ -7,20 +7,16 @@
 
 # third party
 import numpy as np
+import pytest
 
 # current project
 from duventchezmoi.main import compute_mean_wind_speed
 from duventchezmoi.main import write_report
 
 
-def test_compute_mean_speed():
+@pytest.mark.parametrize("units, expected_result", [("km/h", 18.65), ("m/s", 5.18)])
+def test_compute_mean_speed(units, expected_result):
     grib2_file = Path(__file__).parent / "20240330_0000.grib2"
-    units = "km/h"
-    expected_result = 18.65
-    value = compute_mean_wind_speed(grib2_file, units)
-    assert np.round(value, decimals=2) == expected_result
-    units = "m/s"
-    expected_result = 5.18
     value = compute_mean_wind_speed(grib2_file, units)
     assert np.round(value, decimals=2) == expected_result