run-tests: allow some slack about 'waiting on lock' message It is common to run the tests on very loaded machine when concurrent run might take a bit longer. Such message are usually harmless, but anoying as they break the tests. Test that explicitly depends on this value have been adjusted. This make them more robust anyway. A fun case was `test-clone-pull-corruption.t` which, without the previous changeset introducing extra flushing, ended use having a line 31 (`pulling from ../source`) changing order because the warning message was no longer flushing stdin before using stderr (stderr being invisible in the test). Differential Revision: https://phab.mercurial-scm.org/D9507

--- a/tests/test-basic.t	Wed Dec 02 23:15:11 2020 +0100
+++ b/tests/test-basic.t	Wed Dec 02 20:10:27 2020 +0100
@@ -13,6 +13,7 @@
   ui.merge=internal:merge
   ui.mergemarkers=detailed
   ui.promptecho=True
+  ui.timeout.warn=15
   web.address=localhost
   web\.ipv6=(?:True|False) (re)
   web.server-header=testing stub value