Adds CI checks forbidding certain kinds of world loops (#24454)

* Updates checkgrep to report unnecessary loops

* improved message

* global lists are better too

* much better

* Apply suggestions from code review

Co-authored-by: GDN <96800819+GDNgit@users.noreply.github.com>

* update to modern check_grep format

---------

Co-authored-by: GDN <96800819+GDNgit@users.noreply.github.com>
Co-authored-by: S34N <12197162+S34NW@users.noreply.github.com>

code/modules/events/blob/blob_mobs.dm

@@ -20,6 +20,14 @@
 	fire_damage = 3
 	var/mob/camera/blob/overmind = null
 
+/mob/living/simple_animal/hostile/blob/Initialize(mapload)
+	. = ..()
+	GLOB.blob_minions |= src
+
+/mob/living/simple_animal/hostile/blob/Destroy()
+	GLOB.blob_minions -= src
+	return ..()
+
 /mob/living/simple_animal/hostile/blob/proc/adjustcolors(a_color)
 	if(a_color)
 		color = a_color

code/modules/events/blob/blob_powers.dm

@@ -469,7 +469,7 @@
 	for(var/obj/structure/blob/BL in GLOB.blobs)
 		BL.adjustcolors(blob_reagent_datum.color)
 
-	for(var/mob/living/simple_animal/hostile/blob/BLO)
+	for(var/mob/living/simple_animal/hostile/blob/BLO in GLOB.blob_minions)
 		BLO.adjustcolors(blob_reagent_datum.complementary_color)
 
 	to_chat(src, "Your reagent is now: <b><font color=\"[blob_reagent_datum.color]\">[blob_reagent_datum.name]</b></font> - [blob_reagent_datum.description]")

code/modules/events/blob/theblob.dm

@@ -2,6 +2,7 @@
 
 GLOBAL_LIST_EMPTY(blobs)
 GLOBAL_LIST_EMPTY(blob_nodes)
+GLOBAL_LIST_EMPTY(blob_minions)
 
 /obj/structure/blob
 	name = "blob"

code/modules/events/undead_event.dm

@@ -8,7 +8,7 @@
 	RS.lightsoutAmount = pick(2,2,3)
 	RS.start()
 	RS.kill()
-	for(var/area/A)
+	for(var/area/A in GLOB.all_areas)
 		if(!is_station_level(A.z)) continue //Spook on main station only.
 		if(A.luminosity) continue
 //			if(A.lighting_space) continue