Skip cancellable test on Windows too.

Author: ioquatix

test/io/event/selector/cancellable.rb

@@ -42,6 +42,8 @@ def after
 		end
 
 		it "can cancel waits" do
+			skip "Not supported on Windows" if RUBY_PLATFORM =~ /mswin|mingw|cygwin/
+			
 			reader = Fiber.new do
 				buffer = IO::Buffer.new(64)