patch 8.2.5131: timeout implementation is not optimal

Problem:    Timeout implementation is not optimal.
Solution:   Further improvements for timeouts.  Add a test for searchpair()
            timeout. (partly by Paul Ollis)
diff --git a/src/version.c b/src/version.c
index 60c1817..b8bc580 100644
--- a/src/version.c
+++ b/src/version.c
@@ -735,6 +735,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    5131,
+/**/
     5130,
 /**/
     5129,