Fixes shiva panic room insert presets (#7152)

# About the pull request

Survivor doctors and scientists for the shiva snowball panic room
nightmare insert now spawn with the correct presets.

# Explain why it's good for the game

Bad for snow map survivors to have no snow gear.


# Testing Photographs and Procedure
<details>
<summary>Screenshots & Videos</summary>

Put screenshots and videos here with an empty line between the
screenshots and the `<details>` tags.

</details>


# Changelog
:cl:
fix: Scientists and Doctors from the Shiva panic room nightmare insert
now spawn with snow gear as intended.
/:cl:

code/game/objects/effects/landmarks/survivor_spawner.dm

@@ -169,7 +169,7 @@
 	spawn_priority = SPAWN_PRIORITY_VERY_HIGH
 
 /obj/effect/landmark/survivor_spawner/shivas_panic_room_doc
-	equipment = /datum/equipment_preset/survivor/doctor
+	equipment = /datum/equipment_preset/survivor/doctor/shiva
 	synth_equipment = /datum/equipment_preset/synth/survivor/emt_synth
 	intro_text = list("<h2>You are a Medical Doctor on the Colony!</h2>",\
 	"<span class='notice'>You are aware of the xenomorph threat.</span>",\
@@ -179,7 +179,7 @@
 	spawn_priority = SPAWN_PRIORITY_HIGH
 
 /obj/effect/landmark/survivor_spawner/shivas_panic_room_sci
-	equipment = /datum/equipment_preset/survivor/scientist
+	equipment = /datum/equipment_preset/survivor/scientist/shiva
 	synth_equipment = /datum/equipment_preset/synth/survivor/scientist_synth
 	intro_text = list("<h2>You are a Weyland-Yutani Scientist on the Colony!</h2>",\
 	"<span class='notice'>You are aware of the xenomorph threat.</span>",\