Arvados

As evidenced in #12790, there exists a race between when the trash time arrives for a collection, and the next trash sweep. During that period, accessing a collection by PDH results in a 401 ("Expired permission signature"). Tom put it like this:

Even with this config fixed, there's obviously a race condition that we need to fix between when trash time arrives and the next sweep. Here it's just glaringly obvious because the race window is forever.

In #12790 we noticed this problem because trash_sweep_interval was set to 0s.