patch 8.2.5140: seachpair timeout test is flaky

Problem:    Seachpair timeout test is flaky.
Solution:   Mark the test as flaky so it is retried.
diff --git a/src/version.c b/src/version.c
index 370c4d0..5b5b405 100644
--- a/src/version.c
+++ b/src/version.c
@@ -735,6 +735,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    5140,
+/**/
     5139,
 /**/
     5138,