There is a pattern of the notification tests hanging. Whilst we need to get to the
bottom of that, disable them for now as it is causing high load for triage/SWAT
and masking other failures.
[YOCTO #14263]
(From OE-Core rev: 9b96efe8984df955b8880b83b1b48ad9be37863b)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>