[#MDEV-11803] perfschema.stage_mdl_global fails in buildbot on very slow builders

amd64-windows is not a very slow builder (it is extremely fast), and the test failed there:

10.6 7d92c9d212162287b52721fcea1217115853b4f7
perfschema.stage_mdl_global w30 [ fail ]
Test ended at 2022-06-27 10:12:01
CURRENT_TEST: perfschema.stage_mdl_global
--- D:/Buildbot/amd64-windows/build/mysql-test/suite/perfschema/r/stage_mdl_global.result 2022-06-27 10:07:23.000000000 +0200
+++ D:\Buildbot\amd64-windows\build\mysql-test\suite\perfschema\r\stage_mdl_global.reject 2022-06-27 10:12:01.545503700 +0200
@@ -23,8 +23,15 @@
username event_name nesting_event_type
user2 stage/sql/Waiting for backup lock STATEMENT
username event_name nesting_event_type
-user2 stage/sql/starting STATEMENT
-user2 stage/sql/checking permissions STATEMENT
+user2 stage/sql/Waiting for backup lock STATEMENT
+user2 stage/sql/Opening tables STATEMENT
+user2 stage/sql/Waiting for backup lock STATEMENT
+user2 stage/sql/Opening tables STATEMENT
+user2 stage/sql/Waiting for backup lock STATEMENT
+user2 stage/sql/Opening tables STATEMENT
+user2 stage/sql/Waiting for backup lock STATEMENT
+user2 stage/sql/Opening tables STATEMENT
+user2 stage/sql/Waiting for backup lock STATEMENT
user2 stage/sql/Opening tables STATEMENT
connection con1;
unlock tables;
mysqltest: Result length mismatch

Because this test failed as part of mandatory staging build, I think that we should do something about it. The failure output suggests that ~~MDEV-5336~~ (backup locks) could be related to it.

[MDEV-11803] perfschema.stage_mdl_global fails in buildbot on very slow builders Created: 2017-01-15 Updated: 2023-11-28
Status:	Open
Project:	MariaDB Server
Component/s:	Performance Schema, Tests
Affects Version/s:	10.1, 10.3, 10.4, 10.5, 10.6, 10.7, 10.8, 10.9
Fix Version/s:	10.4, 10.5, 10.6

[MDEV-11803] perfschema.stage_mdl_global fails in buildbot on very slow builders Created: 2017-01-15 Updated: 2023-11-28