vim-patch:8.2.4445: exit test fails on MS-Windows anyway

Problem:    Exit test fails on MS-Windows anyway.
Solution:   Skip the test on MS-Windows.
29a9e69718

src/nvim/testdir/test_exit.vim

@@ -114,6 +114,7 @@ func Test_exit_error_reading_input()
   throw 'Skipped: Nvim does not exit after stdin is read'
 
   CheckNotGui
+  CheckNotMSWindows
   " The early exit causes memory not to be freed somehow
   CheckNotAsan