Disable use of account-level ordering options in new room list

Fixes https://github.com/vector-im/riot-web/issues/14069

We can't drop them completely for compatibility with the old room list.

src/settings/Settings.js

@@ -478,11 +478,13 @@ export const SETTINGS = {
             deny: [],
         },
     },
+    // TODO: Remove setting: https://github.com/vector-im/riot-web/issues/14231
     "RoomList.orderAlphabetically": {
         supportedLevels: LEVELS_ACCOUNT_SETTINGS,
         displayName: _td("Order rooms by name"),
         default: false,
     },
+    // TODO: Remove setting: https://github.com/vector-im/riot-web/issues/14231
     "RoomList.orderByImportance": {
         supportedLevels: LEVELS_ACCOUNT_SETTINGS,
         displayName: _td("Show rooms with unread notifications first"),