Disable new PR assignment, just log

[apiraino]

Following discussion on Zulip, I am going to disable the new PR assignment and just log its behaviour.

r? @Kobzol

cc @jackh726

[jackh726]

@apiraino I'm assuming we didn't hit an expect or something because that would have been logged, right?

[apiraino]

@apiraino I'm assuming we didn't hit an expect or something because that would have been logged, right?

Yes, the only important expect I can see here is if the DB query fails being run (which would be a bigger issue).

(The triagebot logs are visible up to INFO level, so they just exclude DEBUG, iiuc)