Migrate `mockito` mocks to `typed_mock` (#24994).

pkg/analyzer_cli/test/plugin_manager_test.dart

Index: pkg/analyzer_cli/test/plugin_manager_test.dart
diff --git a/pkg/analyzer_cli/test/plugin_manager_test.dart b/pkg/analyzer_cli/test/plugin_manager_test.dart
index e48d6e24bf7a18729d14e84dc2a9612b877f102c..16280b223426621af5bcf07aeed33bdf5c0b2504 100644
--- a/pkg/analyzer_cli/test/plugin_manager_test.dart
+++ b/pkg/analyzer_cli/test/plugin_manager_test.dart
@@ -2,12 +2,11 @@
 // 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.
 
-@TestOn("vm")
 library analyzer_cli.test.plugin_manager_test;
 
 import 'package:analyzer/src/plugin/plugin_configuration.dart';
 import 'package:analyzer_cli/src/plugin/plugin_manager.dart';
-import 'package:test/test.dart';
+import 'package:unittest/unittest.dart';
 
 main() {
   group('plugin manager tests', () {