patch 8.2.1369: MS-Windows: autocommand test sometimes fails

Problem:    MS-Windows: autocommand test sometimes fails.
Solution:   Do not rely on the cat command.

Author: brammool

src/testdir/test_autocmd.vim

@@ -1618,7 +1618,7 @@ func Test_change_mark_in_autocmds()
   write
   au! BufWritePre
 
-  if executable('cat')
+  if has('unix')
     write XtestFilter
     write >> XtestFilter
 

src/version.c

@@ -754,6 +754,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1369,
 /**/
     1368,
 /**/