patch 8.2.2099: Vim9: some checks are not tested

Problem:    Vim9: some checks are not tested.
Solution:   Add a few more tests.  Give better error messages.
diff --git a/src/version.c b/src/version.c
index a24a261..9903918 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2099,
+/**/
     2098,
 /**/
     2097,