mark flaky tests as flaky (#69633)

dev/prod_builders.json

@@ -160,13 +160,13 @@
          "name": "Mac build_ios_framework_module_test",
          "repo": "flutter",
          "task_name": "mac_build_ios_framework_module_test",
-         "flaky": false
+         "flaky": true
       },
       {
          "name": "Mac build_tests",
          "repo": "flutter",
          "task_name": "mac_build_tests",
-         "flaky": false
+         "flaky": true
       },
       {
          "name": "Mac build_gallery",

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

@@ -44,7 +44,7 @@ void main() {
     project.uncommentHotReloadPrint();
     try {
       await flutter.hotRestart();
-      await completer.future;
+      await completer.future.timeout(const Duration(seconds: 15));
     } finally {
       await subscription.cancel();
     }
@@ -62,7 +62,7 @@ void main() {
     project.uncommentHotReloadPrint();
     try {
       await flutter.hotRestart();
-      await completer.future;
+      await completer.future.timeout(const Duration(seconds: 15));
     } finally {
       await subscription.cancel();
     }