remove 'mode' from render() for all classic_control envs

fancy_gym/envs/classic_control/hole_reacher/hole_reacher.py

@@ -178,9 +178,7 @@ class HoleReacherEnv(BaseReacherDirectEnv):
 
         return False
 
-    def render(self, mode=None):
-        if mode==None:
-            mode = self.render_mode
+    def render(self):
         if self.fig is None:
             # Create base figure once on the beginning. Afterwards only update
             plt.ion()

fancy_gym/envs/classic_control/simple_reacher/simple_reacher.py

@@ -98,9 +98,7 @@ class SimpleReacherEnv(BaseReacherTorqueEnv):
     def _check_collisions(self) -> bool:
         return self._check_self_collision()
 
-    def render(self, mode=None):  # pragma: no cover
-        if mode==None:
-            mode = self.render_mode
+    def render(self):  # pragma: no cover
         if self.fig is None:
             # Create base figure once on the beginning. Afterwards only update
             plt.ion()

fancy_gym/envs/classic_control/viapoint_reacher/viapoint_reacher.py

@@ -123,9 +123,7 @@ class ViaPointReacherEnv(BaseReacherDirectEnv):
     def _check_collisions(self) -> bool:
         return self._check_self_collision()
 
-    def render(self, mode=None):
-        if mode==None:
-            mode = self.render_mode
+    def render(self):
         goal_pos = self._goal.T
         via_pos = self._via_point.T