BUG: Fix missing titles in roll parameter plots for fin sets

Call set_title(None) on clf_delta and cld_omega after set_inputs/set_outputs
in Fins.evaluate_roll_parameters() so the title is auto-generated from the
updated axis names instead of remaining None.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: Gui-FernandesBR

rocketpy/plots/aero_surface_plots.py

@@ -164,7 +164,6 @@ def roll(self):
         None
         """
         print("Roll parameters:")
-        # TODO: lacks a title in the plots
         self.aero_surface.roll_parameters[0]()
         self.aero_surface.roll_parameters[1]()
 

rocketpy/rocket/aero_surface/fins/fins.py

@@ -328,6 +328,7 @@ def evaluate_roll_parameters(self):
         )  # Function of mach number
         clf_delta.set_inputs("Mach")
         clf_delta.set_outputs("Roll moment forcing coefficient derivative")
+        clf_delta.set_title(None)
         cld_omega = (
             2
             * self.roll_damping_interference_factor
@@ -339,6 +340,7 @@ def evaluate_roll_parameters(self):
         )  # Function of mach number
         cld_omega.set_inputs("Mach")
         cld_omega.set_outputs("Roll moment damping coefficient derivative")
+        cld_omega.set_title(None)
         self.roll_parameters = [clf_delta, cld_omega, self.cant_angle_rad]
         return self.roll_parameters