swapBuffers() call in PGraphicsOpenGL.dispose() is not needed.

core/src/processing/opengl/PGraphicsOpenGL.java

@@ -604,16 +604,6 @@ public class PGraphicsOpenGL extends PGraphics {
   public void dispose() { // PGraphics
     super.dispose();
 
-    if (primaryGraphics) {
-      // Swap buffers the end to make sure that no
-      // garbage is shown on the screen, this particularly
-      // affects non-interactive sketches on windows that
-      // render only 1 frame, so no enough rendering
-      // iterations have been conducted so far to properly
-      // initialize all the buffers.
-      pgl.swapBuffers();
-    }
-
     if (asyncPixelReader != null) {
       asyncPixelReader.dispose();
       asyncPixelReader = null;