ENH: Fixing initial volume calculation for parachute

Author: ArthurJWH

rocketpy/rocket/parachute.py

@@ -212,10 +212,7 @@ def __init__(
         self.height = height or radius
         self.initial_radius = initial_radius or radius
         self.initial_volume = (
-            (4 / 3)
-            * math.pi
-            * (self.parachute_height / self.parachute_radius)
-            * (min(self.parachute_radius, self.rocket.radius)) ** 3
+            (4 / 3) * math.pi * (self.height / self.radius) * self.initial_radius**3
         )
         self.porosity = porosity
         self.added_mass_coefficient = 1.068 * (