Couldn't connect when I tried it

Cast is also not supported by hls-video, can investigate both these together.

web/apps/photos/src/styles/photoswipe.css

@@ -286,7 +286,6 @@ media-time-range:hover {
   they trigger.
  */
 media-pip-button[mediapipunavailable],
-media-airplay-button[mediaairplayunavailable],
 media-fullscreen-button[mediafullscreenunavailable] {
     display: none;
 }

web/packages/gallery/components/viewer/photoswipe.ts

@@ -1295,7 +1295,6 @@ const hlsVideoControlsHTML = () => `
       <svg slot="icon" viewBox="0 0 24 24">${settingsSVGPath}</svg>
     </media-settings-menu-button>
     <media-pip-button></media-pip-button>
-    <media-airplay-button></media-airplay-button>
     <media-fullscreen-button></media-fullscreen-button>
   </media-control-bar>
 </div>