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)
diff --git a/src/version.c b/src/version.c
index 09bbb91..ac574d5 100644
--- a/src/version.c
+++ b/src/version.c
@@ -754,6 +754,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3789,
+/**/
     3788,
 /**/
     3787,