pull request about issue #2062 (car_racing.py memory leaking issue ) (#…

…2096)

* car_racing.py memory leaking issue #2062 solving

* additional memory leaking resolve

gym/envs/box2d/car_racing.py

@@ -528,6 +528,7 @@ def render_road(self):
             len(polygons_) // 3, ("v3f", polygons_), ("c4f", colors)  # gl.GL_QUADS,
         )
         vl.draw(gl.GL_QUADS)
+        vl.delete()
 
     def render_indicators(self, W, H):
         s = W / 40.0
@@ -589,6 +590,7 @@ def horiz_ind(place, val, color):
             len(polygons) // 3, ("v3f", polygons), ("c4f", colors)  # gl.GL_QUADS,
         )
         vl.draw(gl.GL_QUADS)
+        vl.delete()
         self.score_label.text = "%04i" % self.reward
         self.score_label.draw()