[test] Require Dart 3.3, drop dependency on pkg:js

Author: kevmoo

.github/workflows/dart.yml

@@ -1,3 +1,7 @@
+## 1.25.3-wip
+
+* Require Dart 3.3
+
 ## 1.25.2
 
 * Fix a bug running browser tests with paths containing windows directory

pkgs/test/CHANGELOG.md

@@ -112,13 +112,14 @@ class Dart2JsSupport extends CompilerSupport with JsHtmlWrapper {
       var jsPath = p.join(dir, '${p.basename(dartPath)}.browser_test.dart.js');
       var bootstrapContent = '''
         ${suiteConfig.metadata.languageVersionComment ?? await rootPackageLanguageVersionComment}
+        import 'dart:js_interop';
         import 'package:test/src/bootstrap/browser.dart';
         import 'package:test/src/runner/browser/dom.dart' as dom;
 
         import '${await absoluteUri(dartPath)}' as test;
 
         void main() {
-          dom.window.console.log(r'Startup for test path $dartPath');
+          dom.window.console.log(r'Startup for test path $dartPath'.toJS);
           internalBootstrapBrowserTest(() => test.main);
         }
       ''';

pkgs/test/lib/src/runner/browser/compilers/dart2js.dart

@@ -2,10 +2,9 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+import 'dart:js_interop';
 import 'dart:js_util' as js_util;
 
-import 'package:js/js.dart';
-
 @JS()
 @staticInterop
 class Window extends EventTarget {}
@@ -38,8 +37,8 @@ external Window get window;
 class Console {}
 
 extension ConsoleExtension on Console {
-  external void log(Object? object);
-  external void warn(Object? object);
+  external void log(JSString object);
+  external void warn(JSString object);
 }
 
 @JS()
@@ -238,7 +237,7 @@ HTMLIFrameElement createHTMLIFrameElement() =>
 class WebSocket extends EventTarget {}
 
 extension WebSocketExtension on WebSocket {
-  external void send(Object? data);
+  external void send(JSAny? data);
 }
 
 WebSocket createWebSocket(String url) =>

pkgs/test/lib/src/runner/browser/dom.dart

@@ -2,6 +2,7 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+import 'dart:js_interop';
 import 'dart:js_util';
 
 import 'package:stream_channel/stream_channel.dart';
@@ -13,7 +14,7 @@ import 'dom.dart' as dom;
 ///
 /// Sends a [MessagePort] to the host page for the channel.
 StreamChannel<Object?> postMessageChannel() {
-  dom.window.console.log('Suite starting, sending channel to host');
+  dom.window.console.log('Suite starting, sending channel to host'.toJS);
   var controller = StreamChannelController<Object?>(sync: true);
   var channel = dom.createMessageChannel();
   dom.window.parent