patch 8.2.0621: after running tests asan files may remain

Problem:    After running tests asan files may remain.
Solution:   Clean up asan files with "make testclean".
diff --git a/src/version.c b/src/version.c
index a46ffb4..e446e6b 100644
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    621,
+/**/
     620,
 /**/
     619,