Update the copyright text

Author: shahmishal

utils/build-windows.bat

@@ -2,7 +2,7 @@
 ::
 :: This source file is part of the Swift.org open source project
 ::
-:: Copyright (c) 2014 - 2019 Apple Inc. and the Swift project authors
+:: Copyright (c) 2014 - 2021 Apple Inc. and the Swift project authors
 :: Licensed under Apache License v2.0 with Runtime Library Exception
 ::
 :: See https://swift.org/LICENSE.txt for license information