[MIRROR] Fixes bows not loosening their strings once fired (#26697)

* Fixes bows not loosening their strings once fired (#81724)

## About The Pull Request
So, there's this one place that could have just called `clear_chambered`
because it does the exact same operations, but didn't.

Here's `gun/ballistic/proc/clear_chambered()`:

https://github.com/tgstation/tgstation/blob/ce04e2b7ee279e025bd53e87296e7dfd70b9474a/code/modules/projectiles/guns/ballistic.dm#L285-L288

and here's `gun/ballistic/bow/clear_chambered()`, which is responsible
for setting `drawn` to false:

https://github.com/tgstation/tgstation/blob/ce04e2b7ee279e025bd53e87296e7dfd70b9474a/code/modules/projectiles/guns/ballistic/bows/_bow.dm#L52-L54

You can connect the dots.

* Fixes bows not loosening their strings once fired

---------

Co-authored-by: Ghom <42542238+Ghommie@users.noreply.github.com>

code/modules/projectiles/guns/ballistic.dm

@@ -264,8 +264,7 @@
 				casing.bounce_away(TRUE)
 				SEND_SIGNAL(casing, COMSIG_CASING_EJECTED)
 		else if(empty_chamber)
-			UnregisterSignal(chambered, COMSIG_MOVABLE_MOVED)
-			chambered = null
+			clear_chambered()
 	if (chamber_next_round && (magazine?.max_ammo > 1))
 		chamber_round()