patch 8.2.0761: Vim9: instructions not tested

Problem:    Vim9: instructions not tested
Solution:   Use a variable instead of a constant.
diff --git a/src/version.c b/src/version.c
index d447c4b..c631d54 100644
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    761,
+/**/
     760,
 /**/
     759,