patch 8.2.1464: Vim9: build warning for unused variable

Problem:    Vim9: build warning for unused variable.
Solution:   Delete the variable declaration.
diff --git a/src/version.c b/src/version.c
index 864c14b..4554fc4 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1464,
+/**/
     1463,
 /**/
     1462,