fix: make nil action and choregraphy when they are finished

sonic-radiance.love/scenes/battlesystem/controllers/fighters/character.lua

@@ -109,6 +109,7 @@ function HeroFighter:goBackToMenu()
 end
 
 function HeroFighter:finishAction()
+  self.action = nil
   self:setInactive()
 end
 

sonic-radiance.love/scenes/battlesystem/controllers/fighters/systems/actions/parent.lua

@@ -40,6 +40,7 @@ function ActionParent:start()
 end
 
 function ActionParent:choregraphyEnded()
+  self.choregraphy = nil
   self:finishAction()
 end