Remove room recovery reminder

The Secure Backup toast replaces this with better UX.

Part of https://github.com/vector-im/element-web/issues/13895

src/settings/Settings.ts

@@ -281,11 +281,6 @@ export const SETTINGS: {[setting: string]: ISetting} = {
         displayName: _td('Autoplay GIFs and videos'),
         default: false,
     },
-    "showRoomRecoveryReminder": {
-        supportedLevels: LEVELS_ACCOUNT_SETTINGS,
-        displayName: _td('Show a reminder to enable Secure Message Recovery in encrypted rooms'),
-        default: true,
-    },
     "enableSyntaxHighlightLanguageDetection": {
         supportedLevels: LEVELS_ACCOUNT_SETTINGS,
         displayName: _td('Enable automatic language detection for syntax highlighting'),