🩹(frontend) prevent an error if crisp is not defined

While hot reloading the stack, I got an error, Crisp not being
defined at the time of the component rendering. Prevent such issue.
I am not 100% sure this commit is useful, WDYT?

src/frontend/src/features/rooms/livekit/components/controls/SupportToggle.tsx

@@ -9,6 +9,10 @@ export const SupportToggle = () => {
   const [isOpened, setIsOpened] = useState($crisp.is('chat:opened'))
 
   useEffect(() => {
+    if (!Crisp) {
+      return
+    }
+
     Crisp.chat.onChatOpened(() => {
       setIsOpened(true)
     })