patch 8.2.2567: Vim9: no error if variable is defined for existing function

Problem:    Vim9: no error if variable is defined for existing function.
Solution:   Check if name isn't already in use. (closes #7897)
diff --git a/src/version.c b/src/version.c
index c6913d6..879931d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2567,
+/**/
     2566,
 /**/
     2565,