refacter: import하고 사용하지 않고 있던 TransitionGroup 제거

src/pages/SelectPage.tsx

@@ -1,6 +1,6 @@
 import { useState } from "react";
 import { useNavigate } from "react-router-dom";
-import { CSSTransition, TransitionGroup } from "react-transition-group";
+import { CSSTransition } from "react-transition-group";
 
 import { Button } from "@/components/form/Button";
 import { Text } from "@/components/typography";