Multiple flaky test failures in check_runtimes, create_and_destroy

Flaky tests were detected in [this test run](https://github.com/cmss13-devs/cmss13/actions/runs/20989570149/attempts/1). This means that there was a failure that was cleared when the tests were simply restarted.
Failures:
```
create_and_destroy: /obj/item/clothing/gloves/marine/veteran/upp hard deleted 1 times out of a total del count of 5 at code/defines/../modules/unit_tests/create_and_destroy.dm:134
create_and_destroy: /mob/living/carbon/human hard deleted 1 times out of a total del count of 18 at code/defines/../modules/unit_tests/create_and_destroy.dm:134
check_runtimes: [09:47:56]RUNTIME: Cannot read null.z - code/__HELPERS/unsorted.dm@1301 at code/defines/../modules/unit_tests/check_runtimes.dm:10
check_runtimes: [09:47:58]RUNTIME: list index out of bounds - code/controllers/subsystem/sentry.dm@53 at code/defines/../modules/unit_tests/check_runtimes.dm:10
```