Fixes some atom health bugs (#22312)

## About PR
- Fixes #22260
- Fixes #22304
- Fixes #22234

Additionally changes some health values for:

- Canisters, `50` -> `100`. Takes 5 crowbar hits to break instead of 3,
these shouldn't break so easily
- Railings, `30` -> `75`. 3 crowbars instead of 1
- Reinforced girders, `600` -> `300`. Still takes a lot of crowbars
before breaking, barebone girders shouldn't compete reinforced walls

code/game/objects/effects/spiders.dm

@@ -6,7 +6,12 @@
 	anchored = TRUE
 	density = FALSE
 	mouse_opacity = MOUSE_OPACITY_ICON
-	maxhealth = OBJECT_HEALTH_FRAGILE
+	should_use_health = TRUE
+	maxhealth = OBJECT_HEALTH_VERY_LOW
+	armor = list(
+		MELEE = ARMOR_MELEE_MINOR,
+		BULLET = ARMOR_BALLISTIC_MINOR
+	)
 
 //similar to weeds, but only barfed out by nurses manually
 /obj/effect/spider/ex_act(severity)
@@ -21,21 +26,6 @@
 				qdel(src)
 	return
 
-/obj/effect/spider/attackby(obj/item/attacking_item, mob/user)
-	visible_message(SPAN_WARNING("\The [src] has been [LAZYPICK(attacking_item.attack_verb, "attacked")] with [attacking_item][(user ? " by [user]." : ".")]"))
-	var/damage = attacking_item.force / 4.0
-	if(attacking_item.tool_behaviour == TOOL_WELDER)
-		var/obj/item/weldingtool/WT = attacking_item
-		if(WT.use(0, user))
-			damage = 15
-			playsound(loc, 'sound/items/Welder.ogg', 100, 1)
-		return TRUE
-	else
-		user.do_attack_animation(src)
-		playsound(loc, attacking_item.hitsound, 50, 1, -1)
-
-	add_damage(damage)
-
 /obj/effect/spider/bullet_act(obj/projectile/hitting_projectile, def_zone, piercing_hit)
 	. = ..()
 	if(. != BULLET_ACT_HIT)
@@ -258,13 +248,14 @@
 	die()
 
 /obj/effect/spider/spiderling/attackby(obj/item/attacking_item, mob/user)
-	. = ..()
 	if(istype(attacking_item, /obj/item/newspaper))
 		var/obj/item/newspaper/N = attacking_item
 		if(N.rolled)
 			die()
 			return TRUE
 
+	. = ..()
+
 /obj/effect/decal/cleanable/spiderling_remains
 	name = "greimorian larva remains"
 	desc = "Green squishy mess."
@@ -275,7 +266,6 @@
 	name = "cocoon"
 	desc = "Something wrapped in silky greimorian web"
 	icon_state = "cocoon1"
-	maxhealth = OBJECT_HEALTH_VERY_LOW
 
 /obj/effect/spider/cocoon/Initialize()
 	. = ..()