Automate management of self-hosted runners

[mt-caret]

Currently github action runners are spawned manually based off some scripts modified off of https://github.com/stgraber/lxd-github-actions. Every time we run out I need to spend a few minutes copying tokens and spawning a bunch of instances, and it'd be nicer if that is just automated so that there's always a pool of say 10 idle self-hosted runners.