[build-wrangler] Disable test that is failing on windows.

SR-14447

Author: gottesmm

test/Concurrency/Runtime/async_task_handle_cancellation.swift

@@ -9,6 +9,10 @@
 // This test is flaky on VS2017 (unknown reasons)
 // UNSUPPORTED: MSVC_VER=15.0
 
+// This test is failing on windows. SR-14447.
+//
+// UNSUPPORTED: OS=windows-msvc
+
 @available(macOS 9999, iOS 9999, watchOS 9999, tvOS 9999, *)
 @main struct Main {
   static func main() async {