Move web tool test per-test timeout to shard (#78508)

dev/bots/test.dart

@@ -309,6 +309,7 @@ Future<void> _runWebToolTests() async {
           forceSingleCore: true,
           testPaths: <String>[path.join(kTest, '$kWeb$kDotShard', '')],
           enableFlutterToolAsserts: true,
+          perTestTimeout: const Duration(minutes: 3),
         );
       }
   };

dev/prod_builders.json

@@ -1294,7 +1294,7 @@
       "name": "Windows web_tool_tests",
       "repo": "flutter",
       "task_name": "win_web_tool_tests",
-      "flaky": true
+      "flaky": false
     }
   ]
 }

packages/flutter_tools/test/web.shard/debugger_stepping_web_test.dart

@@ -4,7 +4,6 @@
 
 // @dart = 2.8
 
-@Timeout(Duration(minutes: 3))
 import 'package:file/file.dart';
 
 import '../integration.shard/test_data/stepping_project.dart';

packages/flutter_tools/test/web.shard/expression_evaluation_web_test.dart

@@ -4,7 +4,6 @@
 
 // @dart = 2.8
 
-@Timeout(Duration(minutes: 3))
 import 'package:file/file.dart';
 import 'package:matcher/matcher.dart';
 import 'package:vm_service/vm_service.dart';

packages/flutter_tools/test/web.shard/hot_reload_web_test.dart

@@ -4,7 +4,6 @@
 
 // @dart = 2.8
 
-@Timeout(Duration(minutes: 3))
 import 'dart:async';
 
 import 'package:file/file.dart';

packages/flutter_tools/test/web.shard/web_run_test.dart

@@ -4,7 +4,6 @@
 
 // @dart = 2.8
 
-@Timeout(Duration(minutes: 3))
 import 'package:file/file.dart';
 import 'package:flutter_tools/src/base/file_system.dart';