patch 8.2.3898: Vim9: not sufficient testing for variable initialization

Problem:    Vim9: not sufficient testing for variable initialization.
Solution:   Add another test case.
diff --git a/src/version.c b/src/version.c
index adb3722..e41dcb1 100644
--- a/src/version.c
+++ b/src/version.c
@@ -750,6 +750,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3898,
+/**/
     3897,
 /**/
     3896,