patch 8.2.4162: Vim9: no error for redefining function with export

Problem:    Vim9: no error for redefining function with export.
Solution:   Check for existing function with/without prefix. (closes #9577)
diff --git a/src/version.c b/src/version.c
index fae00dc..7fd24f5 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4162,
+/**/
     4161,
 /**/
     4160,