Fixes Bitrunner lacking job-based bounties (#84367)

## About The Pull Request

Fixes #84283 by just adding actual bounties for Bitrunner, giving them
something more interesting to do than random bounties for jobs they
don't have access to. These bounties revolve around optionally turning
in the special rewards from each of the bitrunning domains (a bike horn,
the abductor plush, beach ball, etc) for a credit reward. I considered
the idea of making each one drop a specific bounty chit that you turned
in for a reward, but at that point it's just "paying you per domain" and
I'm not sure how that would balance with economy.

This is more just meant to be a framework for others to add things that
might be a little more interesting.

This also adds a special drop from the Pizzeria domain because I thought
it was funny.

code/modules/bitrunning/job.dm

@@ -13,7 +13,7 @@
 	paycheck = PAYCHECK_CREW
 	paycheck_department = ACCOUNT_CAR
 	display_order = JOB_DISPLAY_ORDER_BITRUNNER
-	bounty_types = CIV_JOB_RANDOM
+	bounty_types = CIV_JOB_BITRUN
 	departments_list = list(
 		/datum/job_department/cargo,
 		)

code/modules/bitrunning/virtual_domain/domains/fredingtonfastingbear.dm

@@ -2,6 +2,7 @@
 	name = "Pizza Party"
 	cost = BITRUNNER_COST_MEDIUM
 	desc = "A famous pizzeria that got ruined by what it had to offer."
+	completion_loot = list(/obj/item/food/pizzaslice/meat/pizzeria = 1)
 	difficulty = BITRUNNER_DIFFICULTY_MEDIUM
 	help_text = "Pick up a flashlight and get going. Your favourite bear has been waiting for you..."
 	key = "fredingtonfastingbear"