patch 8.2.4407: Vim9: some code not covered by tests

Problem:    Vim9: some code not covered by tests.
Solution:   Add more tests.  Avoid giving two errors.  Remove dead code.
diff --git a/src/version.c b/src/version.c
index c304f0c..76d7895 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4407,
+/**/
     4406,
 /**/
     4405,