Enable lint rules for Promise handling to discourage misuse of them. (#2607)

* Enable lint rules for Promise handling to discourage misuse of them.
Squashed all of Hugh's commits into one.

---------

Co-authored-by: Hugh Nimmo-Smith <hughns@element.io>

src/UserMenuContainer.tsx

@@ -31,7 +31,7 @@ export const UserMenuContainer: FC<Props> = ({ preventNavigation = false }) => {
   const [settingsTab, setSettingsTab] = useState(defaultSettingsTab);
 
   const onAction = useCallback(
-    async (value: string) => {
+    (value: string) => {
       switch (value) {
         case "user":
           setSettingsTab("profile");