don't use depth range hack in rect case

src/rendering/twn_gl_any_rendering.c

@@ -74,6 +74,9 @@ void clear_draw_buffer(void) {
     /* TODO: don't clear color when skybox is applied? */
     /*       for that window should match framebuffer */
     /*       also it is driver dependent, from what i can gather */
+    /* INFO: also, based on below, driver might prefer it staying this way */
+    /*       https://gamedev.stackexchange.com/questions/90344/render-with-const-depth-value */
+    /*       we could optionally load ARB_invalidate_subdata extension if it's available instead */
     glClear(GL_COLOR_BUFFER_BIT |
             GL_DEPTH_BUFFER_BIT |
             GL_STENCIL_BUFFER_BIT);