[keyserver] Set a job that synchronizes links with blobs

Summary:
Run this script daily. It should happen after Blob service cleanup, which starts between midnight and 0:15 AM and currently takes up to a couple of minutes.

Depends on D10205

Test Plan: Modify the schedule and check if the script runs.

Reviewers: michal, bartek, rohan

Reviewed By: rohan

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D10206