[MIRROR] Fix build mode preview spawning atoms needlessly [MDB IGNORE…

…] (#25476)

* Fix build mode preview spawning atoms needlessly (#80130)

Before the large icon fix, it would use a mutable_appearance,
get_small_overlay wants atoms but it only does appearance things with
them so images and mutable appearances should work. There is no need to
spawn the atom itself.

We will at some point need a way to specify interfaces as argument
types, many such cases of atom or image or mutable_appearance in icon
related procs.

closes #80125

* Fix build mode preview spawning atoms needlessly

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Co-authored-by: Kyle Spier-Swenson <[email protected]>

code/modules/buildmode/buildmode.dm

@@ -135,7 +135,7 @@
 	preview.name = initial(typepath.name)
 
 	// Scale the preview if it's bigger than one tile
-	var/mutable_appearance/preview_overlay = get_small_overlay(new typepath)
+	var/mutable_appearance/preview_overlay = get_small_overlay(new /mutable_appearance(typepath))
 	preview_overlay.appearance_flags |= TILE_BOUND
 	preview_overlay.layer = FLOAT_LAYER
 	preview_overlay.plane = FLOAT_PLANE