refactor: ♻️ 升级依赖、移除 pdf 预览和修复打包类型警告问题

src/composables/websocket/useDictSync.ts

@@ -1,4 +1,3 @@
-import { ref } from "vue";
 import { useDictStoreHook } from "@/store/modules/dict-store";
 import { useStomp } from "./useStomp";
 import type { IMessage } from "@stomp/stompjs";