patch 8.2.2372: confusing error message for wrong :let command

Problem:    Confusing error message for wrong :let command.
Solution:   Only check for type in Vim9 script.
diff --git a/src/version.c b/src/version.c
index 289854e..3a88080 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2372,
+/**/
     2371,
 /**/
     2370,