Spiderlings can cross webs (#75404)

## About The Pull Request

Reliable web traversal is now governed by a trait instead of a type
check.
Spiderlings have that trait.

## Why It's Good For The Game

Spiderlings are spiders and shouldn't get stuck in webs.
Turning this into a trait means that we can make more things apply the
trait in future if we want, without having to expand a list of allowed
mobs.

## Changelog

🆑
fix: Spiderlings no longer get stuck in webs
/🆑

code/modules/mob/living/basic/space_fauna/spider/giant_spider/giant_spider.dm

@@ -63,6 +63,7 @@
 
 /mob/living/basic/giant_spider/Initialize(mapload)
 	. = ..()
+	ADD_TRAIT(src, TRAIT_WEB_SURFER, INNATE_TRAIT)
 	AddElement(/datum/element/footstep, FOOTSTEP_MOB_CLAW)
 	AddElement(/datum/element/nerfed_pulling, GLOB.typecache_general_bad_things_to_easily_move)
 	AddElement(/datum/element/prevent_attacking_of_types, GLOB.typecache_general_bad_hostile_attack_targets, "this tastes awful!")

code/modules/mob/living/basic/space_fauna/spider/spiderlings/spiderling.dm

@@ -53,9 +53,7 @@
 
 	// the proc that handles passtable is nice but we should always be able to pass through table since we're so small so we can eschew adding that here
 	pass_flags |= PASSTABLE
-	ADD_TRAIT(src, TRAIT_PASSTABLE, INNATE_TRAIT)
-
-	ADD_TRAIT(src, TRAIT_VENTCRAWLER_ALWAYS, INNATE_TRAIT)
+	add_traits(list(TRAIT_PASSTABLE, TRAIT_VENTCRAWLER_ALWAYS, TRAIT_WEB_SURFER), INNATE_TRAIT)
 	AddComponent(/datum/component/swarming)
 	AddElement(/datum/element/footstep, FOOTSTEP_MOB_CLAW, volume = 0.2) // they're small but you can hear 'em