Multiple errors in flaky test omnitools/engiborg

[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:

omnitools/engiborg: [22:19:48] Runtime in code/modules/mob/living/basic/slime/life.dm,19: Cannot execute null.return air().
proc name: handle slime stasis (/mob/living/basic/slime/proc/handle_slime_stasis)
src: the grey baby slime (348) (/mob/living/basic/slime)
src.loc: null
call stack:
the grey baby slime (348) (/mob/living/basic/slime): handle slime stasis(2)
the grey baby slime (348) (/mob/living/basic/slime): Life(2, 13)
Mobs (/datum/controller/subsystem/mobs): fire(1)
Mobs (/datum/controller/subsystem/mobs): ignite(1)
Master (/datum/controller/master): RunQueue()
Master (/datum/controller/master): Loop(2)
Master (/datum/controller/master): StartProcessing(0) at code/modules/mob/living/basic/slime/life.dm:19
omnitools/engiborg: [22:19:48] Runtime in code/modules/mob/living/basic/slime/life.dm,19: Cannot execute null.return air().
proc name: handle slime stasis (/mob/living/basic/slime/proc/handle_slime_stasis)
src: the grey baby slime (937) (/mob/living/basic/slime)
src.loc: null
call stack:
the grey baby slime (937) (/mob/living/basic/slime): handle slime stasis(2)
the grey baby slime (937) (/mob/living/basic/slime): Life(2, 13)
Mobs (/datum/controller/subsystem/mobs): fire(1)
Mobs (/datum/controller/subsystem/mobs): ignite(1)
Master (/datum/controller/master): RunQueue()
Master (/datum/controller/master): Loop(2)
Master (/datum/controller/master): StartProcessing(0) at code/modules/mob/living/basic/slime/life.dm:19
omnitools/engiborg: [22:19:48] Runtime in code/modules/mob/living/basic/slime/life.dm,19: Cannot execute null.return air().
proc name: handle slime stasis (/mob/living/basic/slime/proc/handle_slime_stasis)
src: the grey baby slime (49) (/mob/living/basic/slime)
src.loc: null
call stack:
the grey baby slime (49) (/mob/living/basic/slime): handle slime stasis(2)
the grey baby slime (49) (/mob/living/basic/slime): Life(2, 13)
Mobs (/datum/controller/subsystem/mobs): fire(1)
Mobs (/datum/controller/subsystem/mobs): ignite(1)
Master (/datum/controller/master): RunQueue()
Master (/datum/controller/master): Loop(2)
Master (/datum/controller/master): StartProcessing(0) at code/modules/mob/living/basic/slime/life.dm:19