newsletter: Use an audio-enabled playback speed demo in June newsletter

Author: awesomekling

public/assets/img/newsletter-june-2026-playback-rate.mp4

@@ -67,16 +67,9 @@ There's also a new script sources view with pretty-printing, folding, search, an
 
 ### Media: playback speed and muted autoplay
 
-You can now change media playback speed ([#9925](https://github.com/LadybirdBrowser/ladybird/pull/9925)). Audio is time-stretched using Chromium's WSOLA algorithm, so speeding a video up or slowing it down keeps speech intelligible and music reasonable.
+You can now change media playback speed ([#9925](https://github.com/LadybirdBrowser/ladybird/pull/9925)). Audio is time-stretched using Chromium's WSOLA algorithm, so the pitch stays put and speech stays intelligible whether you speed a clip up or slow it down. Here it is at a few different speeds, with sound:
 
-<video
-  autoplay
-  loop
-  muted
-  playsinline
-  controls
-  style="max-width: 100%; margin-bottom: 1em;"
->
+<video controls playsinline style="max-width: 100%; margin-bottom: 1em;">
   <source
     src="/assets/img/newsletter-june-2026-playback-rate.mp4"
     type="video/mp4"