replace yarn with pnpm (#85)

* 🐳 chore: replace yarn with pnpm

easytier-gui/src-tauri/tauri.conf.json

@@ -1,7 +1,7 @@
 {
   "build": {
-    "beforeDevCommand": "yarn dev",
-    "beforeBuildCommand": "yarn build",
+    "beforeDevCommand": "pnpm dev",
+    "beforeBuildCommand": "pnpm build",
     "devPath": "http://localhost:1420",
     "distDir": "../dist"
   },
@@ -46,4 +46,4 @@
       ]
     }
   }
-}
+}