patch 8.2.4629: flattennew() makes a deep copy unnecessarily

Problem:    flattennew() makes a deep copy unnecessarily.
Solution:   Use a shallow copy. (issue #10012)
diff --git a/src/version.c b/src/version.c
index 60b4c1d..a68c881 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4629,
+/**/
     4628,
 /**/
     4627,