Pants (but mostly jeans) resprite (#21863)

pant.
How I forgot how pants should look like: the PR.

From the changelog:
> - imageadd: "Resprited all jeans, black pants and colorable dress
pants."
> - rscdel: "Removed tan, khaki, red, white pants due to the existance
of colorable dress pants. All maps and outfits where these were used now
use black pants (I did not want to put in the effort)."

Images, as always, in the details below.
Old (current) sprites on the top, new on the bottom unless stated
otherwise.
<img width="2560" height="1024" alt="jeans"
src="https://github.com/user-attachments/assets/9290ec78-638d-4c8a-871b-e74022188749"
/>
Do yell at me if these don't look like jeans. Also imagine these but
shorter, now you have jean shorts, which were also resprited.

code/modules/client/preference_setup/loadout/items/pants.dm

@@ -16,11 +16,7 @@ ABSTRACT_TYPE(/datum/gear/pants)
 	pants["classic jeans"] = /obj/item/clothing/pants/classic
 	pants["mustang jeans"] = /obj/item/clothing/pants/mustang
 	pants["black jeans"] = /obj/item/clothing/pants/jeansblack
-	pants["white pants"] = /obj/item/clothing/pants/white
 	pants["black pants"] = /obj/item/clothing/pants/black
-	pants["red pants"] = /obj/item/clothing/pants/red
-	pants["tan pants"] = /obj/item/clothing/pants/tan
-	pants["khaki pants"] = /obj/item/clothing/pants/khaki
 	pants["track pants"] = /obj/item/clothing/pants/track
 	pants["blue track pants"] = /obj/item/clothing/pants/track/blue
 	pants["green track pants"] = /obj/item/clothing/pants/track/green
@@ -35,8 +31,6 @@ ABSTRACT_TYPE(/datum/gear/pants)
 	// Shorts
 	pants["black shorts"] = /obj/item/clothing/pants/shorts/black
 	pants["black short shorts"] = /obj/item/clothing/pants/shorts/black/short
-	pants["khaki shorts"] = /obj/item/clothing/pants/shorts/khaki
-	pants["khaki short shorts"] = /obj/item/clothing/pants/shorts/khaki/short
 
 	// Jeans Shorts
 	pants["jeans shorts"] = /obj/item/clothing/pants/shorts/jeans