artemis plugin does not cancel beaker guest after SIGTERM

[thrix]

See this report:

https://issues.redhat.com/browse/TFT-2471

After SIGTERM tmt finished with 0, seems some signal handling issues maybe (destroy did not run).

[08:02:54] [W] [worker_0] [stderr] [RHEL-9.4.0-Nightly:x86_64:/plans/nay] [server-1]         guest: has been requested[0m
[08:05:26] [W] [Thread-1] [testing-farm-request] Cancelling pipeline as requested
[08:05:26] [W] Interrupted by SIGTERM[0m
[08:05:26] [W] Sending SIGTERM to child process 'tmt' (PID 102)
[08:05:26] [W] [worker_0] [stderr] [RHEL-9.4.0-Nightly:x86_64:/plans/nay] [server-1]         guestname: 4f34a1f8-2443-455f-a5a8-70b41d72a1da
[08:05:26] [+] ---^---^---^---^---^--- End of command output
[08:05:26] [+] [worker_0] [test-schedule-tmt-multihost] tmt exited with code 0

http://artifacts.osci.redhat.com/testing-farm/90c29f96-66dd-43a6-b85b-f78634f624e2/pipeline.log http://artifacts.osci.redhat.com/testing-farm/90c29f96-66dd-43a6-b85b-f78634f624e2/work-naysfc4zleb/log.txt