Space heaters heat up a wider area (#71793)

## About The Pull Request
Space heaters now heat up the 4 tiles near it other than the one it's on
making the process of changing the room temperature much faster even at
lower tier parts.
## Why It's Good For The Game
Makes space heaters a more viable solution at fixing atmos temperature
issues since they affect a wider area
## Changelog
🆑
balance: space heaters also affect the adjacent tiles other than the one
they are on
/🆑

code/game/machinery/spaceheater.dm

@@ -140,8 +140,10 @@
 	if(mode == HEATER_MODE_COOL)
 		delta_temperature *= -1
 	if(delta_temperature)
-		enviroment.temperature += delta_temperature
-		air_update_turf(FALSE, FALSE)
+		for (var/turf/open/turf in ((local_turf.atmos_adjacent_turfs || list()) + local_turf))
+			var/datum/gas_mixture/turf_gasmix = turf.return_air()
+			turf_gasmix.temperature += delta_temperature
+			air_update_turf(FALSE, FALSE)
 	cell.use(required_energy / efficiency)
 
 /obj/machinery/space_heater/RefreshParts()