Replace many usages of useObservableEagerState with useBehavior

This hook is simpler in its implementation (therefore hopefully more correct & performant) and enforces a type-level distinction between raw Observables and Behaviors.

src/room/GroupCallView.tsx

@@ -24,7 +24,6 @@ import {
   type MatrixRTCSession,
 } from "matrix-js-sdk/lib/matrixrtc";
 import { useNavigate } from "react-router-dom";
-import { useObservableEagerState } from "observable-hooks";
 
 import type { IWidgetApiRequest } from "matrix-widget-api";
 import {
@@ -72,6 +71,7 @@ import {
 import { useTypedEventEmitter } from "../useEvents";
 import { muteAllAudio$ } from "../state/MuteAllAudioModel.ts";
 import { useAppBarTitle } from "../AppBar.tsx";
+import { useBehavior } from "../useBehavior.ts";
 
 declare global {
   interface Window {
@@ -110,7 +110,7 @@ export const GroupCallView: FC<Props> = ({
   );
   const memberships = useMatrixRTCSessionMemberships(rtcSession);
 
-  const muteAllAudio = useObservableEagerState(muteAllAudio$);
+  const muteAllAudio = useBehavior(muteAllAudio$);
   const leaveSoundContext = useLatest(
     useAudioContext({
       sounds: callEventAudioSounds,