We want to have the repos and the archive on different servers, to
ensure separation of concerns.

The I/O on gemini is also very sluggish, which is likely related to the
archive design (millions of files on spinning rust), and this has
resulted in rsync deleting the package database files due to a race
condtion[1][2]. The does not solve the race condition, but it should
make it less likely.

We also need to rethink the archive design, but for now we are just
isolating the problem.

There is some "brokenness" related to the archive no longer being on the
same server as the repos, which will be fixed in subsequent commits.

[1] https://lore.kernel.org/linux-btrfs/00ed09b9-d60c-4605-b3b6-f4e79bf92fca@foutras.com/
[2] https://lore.kernel.org/linux-btrfs/ZP8AWKMVYOY0mAwq@debian0.Home/

Relates to #531