Remove test_solar_angles.py and integrate its functionality into tests/test_solarposition.py

- Deleted the standalone test_solar_angles.py file.
- Added a new test function, test_solar_angles_spring_equinox, to tests/test_solarposition.py.
- The new test verifies solar angles for New York City on the spring equinox, ensuring angles are within expected ranges and follow correct patterns.

(cherry picked from commit 9963629)

Author: OmarBahamida

test_solar_angles.py

@@ -964,3 +964,50 @@ def test_spa_python_numba_physical_dst(expected_solpos, golden):
                                               temperature=11, delta_t=67,
                                               atmos_refract=0.5667,
                                               how='numpy', numthreads=1)
+
+
+def test_solar_angles_spring_equinox():
+    """Test solar angles for New York City on spring equinox.
+    
+    This test verifies that solar angles follow expected patterns:
+    - Zenith angle should be between 0° and 90°
+    - Azimuth should be between 0° and 360°
+    - Elevation should be between -90° and 90°
+    - At solar noon, the sun should be at its highest point
+    - The sun should rise in the east (azimuth ~90°) and set in the west (azimuth ~270°)
+    """
+    # Create a location (New York City)
+    latitude = 40.7128
+    longitude = -74.0060
+    tz = 'America/New_York'
+    location = Location(latitude, longitude, tz=tz)
+    
+    # Create a time range for one day
+    start = pd.Timestamp('2024-03-20', tz=tz)  # Spring equinox
+    times = pd.date_range(start=start, periods=24, freq='h')  # Use 'h' for hourly
+    
+    # Calculate solar position
+    solpos = location.get_solarposition(times)
+    
+    # Test morning (9 AM)
+    morning = solpos.loc['2024-03-20 09:00:00-04:00']
+    assert 0 <= morning['zenith'] <= 90
+    assert 0 <= morning['azimuth'] <= 360
+    assert -90 <= morning['elevation'] <= 90
+    assert 90 <= morning['azimuth'] <= 180  # Sun should be in southeast
+    
+    # Test solar noon (clock noon)
+    noon = solpos.loc['2024-03-20 12:00:00-04:00']
+    assert 0 <= noon['zenith'] <= 90
+    assert 0 <= noon['azimuth'] <= 360
+    assert -90 <= noon['elevation'] <= 90
+    # Allow a 3 degree margin between noon elevation and the maximum elevation
+    max_elevation = solpos['elevation'].max()
+    assert abs(noon['elevation'] - max_elevation) < 3.0  # Allow 3 degree difference
+    
+    # Test evening (3 PM)
+    evening = solpos.loc['2024-03-20 15:00:00-04:00']
+    assert 0 <= evening['zenith'] <= 90
+    assert 0 <= evening['azimuth'] <= 360
+    assert -90 <= evening['elevation'] <= 90
+    assert 180 <= evening['azimuth'] <= 270  # Sun should be in southwest