Fix play of second leave sound

src/room/GroupCallView.tsx

@@ -318,12 +318,24 @@ export const GroupCallView: FC<Props> = ({
     (
       reason: "timeout" | "user" | "allOthersLeft" | "decline" | "error",
     ): void => {
-      let playSound: CallEventSounds = "left";
-      if (reason === "timeout" || reason === "decline") playSound = reason;
+      let audioPromise: Promise<void> | undefined = undefined;
+      switch (reason) {
+        case "allOthersLeft":
+          // When "allOthersLeft", the leaveSoundEffect$ in CallEventAudioRenderer
+          // already plays the "left" sound when the remote participant's media
+          // disappears. Playing it here too would cause the sound to play twice.
+          break;
+        case "timeout":
+        case "decline":
+          audioPromise = leaveSoundContext.current?.playSound(reason);
+          break;
+        default:
+          audioPromise = leaveSoundContext.current?.playSound("left");
+      }
 
       setJoined(false);
       setLeft(true);
-      const audioPromise = leaveSoundContext.current?.playSound(playSound);
+
       // We need to wait until the callEnded event is tracked on PostHog,
       // otherwise the iframe may get killed first.
       const posthogRequest = new Promise((resolve) => {