MNt: refactoring get_drag_coefficient in flight.py

- MNT: velocity_body was not being used in get_drag_coefficient, removed it as an input

Author: aZira371

rocketpy/simulation/flight.py

@@ -1380,7 +1380,7 @@ def lateral_surface_wind(self):
         return -wind_u * np.cos(heading_rad) + wind_v * np.sin(heading_rad)
 
     def __get_drag_coefficient(
-        self, drag_function, mach, z, velocity_body, freestream_velocity_body
+        self, drag_function, mach, z, freestream_velocity_body
     ):
         """Calculate drag coefficient, handling both 1D and multi-dimensional functions.