Blood worms are no longer fully immune to space/cold (#96385)

## About The Pull Request

Blood worms take 2 damage/second from being in extreme pressure, and 1
damage/second from being in extreme cold

Note that it doesn't stop their regen (up to 0.5 damage/secon) so the
number is closer to 1.5 damage/second and 0.5 damage/second (for the
elders)

## Why It's Good For The Game

Blood Worm's space immunity is kind of at odds with their intended
design/gameplay loop of stealing people's identities, as more often than
not, the identities they steal are not immune to space.

It is not an uncommon sight to see bworms completely ditch the disguise
mechanic and just go around busting windows to "expand their domain" of
places that they can't be chased

Thus I am opting to remove the full immunity to pressure and cold from
bworms. They are still quite resilient to pressure and cold (if my math
is correct it would take at least a minute to die to pressure damage as
an elder) but lacking full immunity should disincentivize them from
spacing themselves unless in complete necessity.


## Changelog

🆑 Melbert
balance: Blood worms are no longer fully immune to extreme pressures and
cold, such as the vacuum of space
/🆑

code/modules/antagonists/blood_worm/blood_worm_mob.dm

@@ -24,11 +24,12 @@
 	attack_verb_continuous = "bites"
 	attack_verb_simple = "bite"
 
-	minimum_survivable_temperature = 0
+	minimum_survivable_temperature = ICEBOX_MIN_TEMPERATURE
 	maximum_survivable_temperature = T0C + 100
-	unsuitable_cold_damage = 0
+	unsuitable_cold_damage = 1
+	unsuitable_atmos_damage = 2
 
-	habitable_atmos = null
+	habitable_atmos = list("min_oxy" = 5, "max_oxy" = 0)
 
 	// A vivid red.
 	lighting_cutoff_red = 40