Fixes being able to dismantle exoplanet turfs (#15995)

* Exoplanet turfs fix

* Fixes for real

code/modules/overmap/exoplanets/turfs.dm

@@ -5,6 +5,7 @@
 	has_resources = 1
 	footstep_sound = /singleton/sound_category/asteroid_footstep
 	turf_flags = TURF_FLAG_BACKGROUND
+	flags = null
 	var/diggable = 1
 	var/dirt_color = "#7c5e42"
 	var/has_edge_icon = TRUE
@@ -37,8 +38,6 @@
 		if(T.use(1))
 			playsound(src, 'sound/items/Deconstruct.ogg', 80, 1)
 			ChangeTurf(/turf/simulated/floor, FALSE, FALSE, TRUE)
-	else
-		..()
 
 /turf/simulated/floor/exoplanet/ex_act(severity)
 	switch(severity)