feat: update flutter to v3.24 (#865)

ui/flutter/web/index.html

@@ -18,41 +18,21 @@
 
   <meta charset="UTF-8">
   <meta content="IE=Edge" http-equiv="X-UA-Compatible">
-  <meta name="description" content="A new Flutter project.">
+  <meta name="description" content="A modern download manager.">
 
   <!-- iOS meta tags & icons -->
   <meta name="apple-mobile-web-app-capable" content="yes">
   <meta name="apple-mobile-web-app-status-bar-style" content="black">
-  <meta name="apple-mobile-web-app-title" content="gopeed">
+  <meta name="apple-mobile-web-app-title" content="Gopeed">
   <link rel="apple-touch-icon" href="icons/Icon-192.png">
 
   <!-- Favicon -->
   <link rel="icon" type="image/png" href="favicon.png"/>
 
-  <title>gopeed</title>
+  <title>Gopeed</title>
   <link rel="manifest" href="manifest.json">
-
-  <script>
-    // The value below is injected by flutter build, do not touch.
-    var serviceWorkerVersion = null;
-  </script>
-  <!-- This script adds the flutter initialization JS code -->
-  <script src="flutter.js" defer></script>
 </head>
 <body>
-  <script>
-    window.addEventListener('load', function(ev) {
-      // Download main.dart.js
-      _flutter.loader.loadEntrypoint({
-        serviceWorker: {
-          serviceWorkerVersion: serviceWorkerVersion,
-        }
-      }).then(function(engineInitializer) {
-        return engineInitializer.initializeEngine();
-      }).then(function(appRunner) {
-        return appRunner.runApp();
-      });
-    });
-  </script>
+<script src="flutter_bootstrap.js" async></script>
 </body>
-</html>
+</html>