patch 8.2.3789: Test_window_minimal_size can fail on a slow machine

Problem:    Test_window_minimal_size can fail on a slow machine.
Solution:   Do not rely on timers firing at the expected time. (Ozaki Kiichi,
            closes #9335)

src/version.c

@@ -753,6 +753,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3789,
 /**/
     3788,
 /**/