[MIRROR] Updates check_grep to guard against unparsed map variables [MDB IGNORE] (#18299)

* Updates check_grep to guard against unparsed map variables (#72161)

## About The Pull Request

In `/datum/parsed_map/proc/parse_constant()` (via
https://github.com/san7890/bruhstation/blob/b3851d607f85c18edee0149d72922df8e077a46c/code/modules/mapping/reader.dm#L930'),
we do not check (ignore) five different things: `new()`, `newlist()`,
`icon()`, `matrix()`, and `sound()`. Since it's completely useless to
put it in a map and expect to see it code-side now-a-days, let's lint
against it just to be safe in the future.
## Why It's Good For The Game

Prevents silliness like in #72157 (which this PR is also reliant on for
checks to pass).

no changelog needed

* Updates check_grep to guard against unparsed map variables

* centcom toilets

* blackmarket, which somehow just got the snap pops

Co-authored-by: san7890 <the@san7890.com>
Co-authored-by: Zonespace <41448081+Zonespace27@users.noreply.github.com>
Co-authored-by: tastyfish <crazychris32@gmail.com>

_maps/RandomRuins/SpaceRuins/skyrat/blackmarket.dmm

@@ -60,8 +60,7 @@
 /turf/open/floor/iron/dark/textured_large,
 /area/ruin/space/has_grav/powered/skyrat/blackmarket)
 "ht" = (
-/obj/structure/toilet{
-	contents = newlist(/obj/item/toy/snappop/phoenix);
+/obj/structure/toilet/snappop{
 	dir = 4
 	},
 /obj/effect/turf_decal/bot_white,

modular_skyrat/modules/mapping/code/furniture.dm

@@ -63,3 +63,7 @@
 	desc = "It's kind of fun to go up or down these once in a while."
 	icon = 'modular_skyrat/modules/mapping/icons/unique/furniture.dmi'
 	icon_state = "ladder"
+
+// Toilet with a snap pop.
+/obj/structure/toilet/snappop
+	contents = newlist(/obj/item/toy/snappop/phoenix)

tools/ci/check_grep.sh

@@ -95,6 +95,12 @@ if $grep '/obj/structure/cable(/\w+)+[{]' $map_files;	then
     echo -e "${RED}ERROR: Variable editted cables detected, please remove them.${NC}"
     st=1
 fi;
+part "invalid map procs"
+if $grep '(new|newlist|icon|matrix|sound)\(.+\)' $map_files;	then
+	echo
+	echo -e "${RED}ERROR: Using unsupported procs in variables in a map file! Please remove all instances of this.${NC}"
+	st=1
+fi;
 part "invalid cables"
 if $grep '\td[1-2] =' $map_files;	then
 	echo