Add failing test to close the tree for #94356 (#94365)

packages/flutter_tools/test/general.shard/failing_test.dart

+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import '../src/common.dart';
+
+// This is a test that we can use to close the tree until
+// https://github.com/flutter/flutter/issues/74529 is addressed.
+
+void main() {
+  test('Fail unconditionally', () { // ignore: void_checks
+    fail('Failing to close the tree for https://github.com/flutter/flutter/issues/94356');
+  }); // Skip this test to re-open the tree.
+}