Skip test failure with mswin platform

  https://github.com/ruby/win32ole/actions/runs/4507614838/jobs/7935550685?pr=18

Author: hsbt

test/win32ole/test_win32ole.rb

@@ -335,6 +335,8 @@ def test_s_codepage_set
     end
 
     def test_s_codepage_changed
+      omit if RUBY_PLATFORM.match("mswin")
+
       cp = WIN32OLE.codepage
       fso = WIN32OLE.new("Scripting.FileSystemObject")
       fname = fso.getTempName