Cleanup: DRW: Resolve warning about unused variable in release

source/blender/draw/intern/draw_context.cc

@@ -1542,6 +1542,7 @@ void DRW_draw_render_loop_offscreen(Depsgraph *depsgraph,
   /* TODO(fclem): We might want to differentiate between render preview and offscreen render in the
    * future. The later can do progressive rendering. */
   BLI_assert(is_xr_surface == !is_image_render);
+  UNUSED_VARS_NDEBUG(is_image_render);
   DRWContext::Mode mode = is_xr_surface ? DRWContext::VIEWPORT_XR : DRWContext::VIEWPORT_RENDER;
 
   DRWContext draw_ctx(mode, depsgraph, render_viewport, nullptr, region, v3d);