Removes footprints from (most) exoplanet turfs (#20306)

See title. It's pretty soulful for shuttles, but it's incredibly
irritating for any buildings on exoplanets in which you mess up all the
flooring if you take so much as one step outside.

code/modules/mining/mine_turfs.dm

@@ -725,6 +725,7 @@ var/list/mineral_can_smooth_with = list(
 	var/digging
 	has_resources = 1
 	footstep_sound = /singleton/sound_category/asteroid_footstep
+	does_footprint = TRUE
 
 	roof_type = null
 	turf_flags = TURF_FLAG_BACKGROUND