patch 8.2.3895: Vim9: confusing error when using function() with a number

Problem:    Vim9: confusing error when using function() with a number.
Solution:   Check for a function or string argument.
diff --git a/src/version.c b/src/version.c
index c4e4ad0..80d92fc 100644
--- a/src/version.c
+++ b/src/version.c
@@ -750,6 +750,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3895,
+/**/
     3894,
 /**/
     3893,