Make spatial audio Firefox-only

Hopefully explained in comment: we have a heisenbug where we sometimes
lack audio from a certain participant, so this simplifies the audio
path by removing the workaround required to do AEC with spatial audio
on chrome.

src/settings/SettingsModal.tsx

@@ -32,6 +32,7 @@ import {
   useSpatialAudio,
   useShowInspector,
   useOptInAnalytics,
+  canEnableSpatialAudio,
 } from "./useSetting";
 import { FieldRow, InputField } from "../input/Input";
 import { Button } from "../button";
@@ -115,9 +116,14 @@ export const SettingsModal = (props: Props) => {
               label={t("Spatial audio")}
               type="checkbox"
               checked={spatialAudio}
-              description={t(
-                "This will make a speaker's audio seem as if it is coming from where their tile is positioned on screen. (Experimental feature: this may impact the stability of audio.)"
-              )}
+              disabled={!canEnableSpatialAudio()}
+              description={
+                canEnableSpatialAudio()
+                  ? t(
+                      "This will make a speaker's audio seem as if it is coming from where their tile is positioned on screen. (Experimental feature: this may impact the stability of audio.)"
+                    )
+                  : t("This feature is only supported on Firefox.")
+              }
               onChange={(event: React.ChangeEvent<HTMLInputElement>) =>
                 setSpatialAudio(event.target.checked)
               }