Deduplicate authorized_projects queue

This queue can have many duplicate jobs. In #215 (comment 318559897), I outlined how in a recent incident, the vast majority of the jobs were duplicates ('Other' is other jobs with duplicates):

It looks like deduplication would have helped a lot: https://log.gprd.gitlab.net/goto/8e263e9bd209b264f1b245f0ca30bba5

json.duplicate-of.keyword: Descending	Count
Missing	8,325
3ee914e27ba762352b6a5e75	215
f9630c029fb2c5b8880fd4cb	215
4561ec0d8d9869b474eacc52	26
69cb9d685682384501a1d8ef	25
a1c5f034960be79257230048	25
181fc538e707c2ca6016a612	24
22d7a784d3e3cc049bb10462	24
347b3a92feefbe04b3bb2d47	24
43dde2f6b1859944720d07cc	24
Other	402,834

We enabled deduplication for this queue in #42 (comment 318078109).

We can watch the logs at this (long) Kibana link.

From &176 (comment 318144098):

I think around 08:00 UTC today

We would have seen a higher peak without deduplication: