WM: disable idle event handling timer when simulating events

source/blender/windowmanager/intern/wm_window.c

@@ -1563,8 +1563,11 @@ void wm_window_process_events(const bContext *C)
   has_event |= wm_xr_events_handle(CTX_wm_manager(C));
 #endif
 
-  /* no event, we sleep 5 milliseconds */
-  if (has_event == false) {
+  /* When there is no event, sleep 5 milliseconds not to use too much CPU when idle.
+   *
+   * Skip sleeping when simulating events so tests don't idle unnecessarily as simulated
+   * events are typically generated from a timer that runs in the main loop. */
+  if ((has_event == false) && !(G.f & G_FLAG_EVENT_SIMULATE)) {
     PIL_sleep_ms(5);
   }
 }