Update notifications.js (#18977)

app/javascript/mastodon/reducers/notifications.js

@@ -234,8 +234,6 @@ export default function notifications(state = initialState, action) {
   case FOLLOW_REQUEST_AUTHORIZE_SUCCESS:
   case FOLLOW_REQUEST_REJECT_SUCCESS:
     return filterNotifications(state, [action.id], 'follow_request');
-  case ACCOUNT_MUTE_SUCCESS:
-    return action.relationship.muting_notifications ? filterNotifications(state, [action.relationship.id]) : state;
   case NOTIFICATIONS_CLEAR:
     return state.set('items', ImmutableList()).set('pendingItems', ImmutableList()).set('hasMore', false);
   case TIMELINE_DELETE: