patch 9.0.1396: sort(list, 'N') does not work in Vim9 script context

Problem:    sort(list, 'N') does not work in Vim9 script context.
Solution:   Convert string to number without giving an error. (closes #12061)
diff --git a/src/version.c b/src/version.c
index 82d89c1..24c6fa3 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1396,
+/**/
     1395,
 /**/
     1394,