[MIRROR] [NO GBP] The deathmatch modifiers modal menu can actually be opened now. (#26942)

* [NO GBP] The deathmatch modifiers modal menu can actually be opened now. (#82041)

## About The Pull Request
I've fucked up the logic, so it requires the user to be both the host
and an admin to open it, which was the case when I tested it locally.
This PR fixes that and other issues (and **un**dumbs some of the code).
The spinning screen modifier has also been scrapped for being downright
awful and breaking my screen.

## Why It's Good For The Game
Fixing stuff I've thankfully noticed early.

## Changelog

🆑
fix: The deathmatch modifiers modal menu can actually be opened now.
Also fixed a bunch of issues it had.
/🆑

* [NO GBP] The deathmatch modifiers modal menu can actually be opened now.

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

code/datums/components/riding/riding_mob.dm

@@ -459,6 +459,9 @@
 	keytype = /obj/item/key/lasso
 	vehicle_move_delay = 4
 
+/datum/component/riding/creature/goliath/deathmatch
+	keytype = null
+
 /datum/component/riding/creature/goliath/Initialize(mob/living/riding_mob, force, ride_check_flags, potion_boost)
 	. = ..()
 	var/mob/living/basic/mining/goliath/goliath = parent