As tazjin pointed out, this is little enough code that pulling it from a
global channel is a little silly, so I've just inlined everything.
Change-Id: I8750f139a3124135a72737c381215a6e812ce0c3
Reviewed-on: https://cl.tvl.fyi/c/depot/+/882
Tested-by: BuildkiteCI
Reviewed-by: lukegb <lukegb@tvl.fyi>
Reviewed-by: BuildkiteCI