whitby: GC root depot canon

Opened by lukegb at 2021-04-03T16·09+00

As part of the buildkite setup, we should make sure that the most recent canon (successful canon only?) is a GC root, so we can better collect-garbage with impunity.

  1. Done in cl/2904

    tazjin at 2021-05-24T21·57+00

  2. tazjin closed this issue at 2021-05-24T21·57+00