dirmgr got stuck and keeps using old consensus

In my test setup, my Arti uses an old consensus:

2023-03-31T14:57:03.734997Z  INFO tor_dirmgr::state: The current consensus is fresh until 2023-03-30 12:00:00.0 +00:00:00, and valid until 2023-03-30 14:00:00.0 +00:00:00. I've picked 2023-03-30 13:12:46.243009444 +00:00:00 as the earliest time to replace it.

Blowing away .cache/arti fixes it; putting the "busted" one back repro's the bug on every startup of arti.