patch 8.2.4784: lamba test with timer is flaky

Problem:    Lamba test with timer is flaky.
Solution:   Adjust sleep time on retry.
diff --git a/src/version.c b/src/version.c
index a66d7d5..285bced 100644
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4784,
+/**/
     4783,
 /**/
     4782,