Multiple errors in flaky test create_and_destroy

[github-actions]

Flaky tests were detected in this test run. This means that there was a failure that was cleared when the tests were simply restarted.
Failures:

create_and_destroy: /obj/effect/decal/cleanable/ash hard deleted 1 times out of a total del count of 11 at code/modules/unit_tests/create_and_destroy.dm:99
create_and_destroy: /obj/effect/decal/cleanable/glass/titanium hard deleted 1 times out of a total del count of 2 at code/modules/unit_tests/create_and_destroy.dm:99