`low_power` example does not work on WASM

## Bevy version

0.14

## What you did

1. Run the web example: https://bevyengine.org/examples/window/low-power/
2. Press space until you get to the third mode, with `RequestRedraw` being sent

## What went wrong

The event loop should run continuously as long as the event is being sent. However, it does not.

## Additional information

`let _ = event_loop_proxy.send_event(WakeUp);` was added to the example, but the docs all refer to `RequestRedraw`. Replacing the event loop proxy wakeup with `RequestRedraw` appears to fix the behavior.

The event loop proxy is useful when waking from another thread, but it appears it is not a direct replacement for the bevy event on all platforms.