Adds a new tagging system to Buildkite agents, where agents are tagged with
large/small slots. All agents have small slots, only some agents have large
slots. The small slots are purely informative - nothing targets them, whereas
large slots will be used for filtering agents.
This allows us to target large slots in some builds and minimise the concurrent
execution of extremely large builds, while keeping a large number of small slots
around for all the light targets.
This will need some tuning over time (also because tagging is a manual process).
Change-Id: I15aa657773ed874d84d98e55238fb31c75d4efa7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/13120
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2d989ef6cb