[DevOps] - Self-host github build runners to validate buildroot builds

[jr1221]

Current Features

Right now, the reviewer of a PR has to wait the hour or so for the specific defconfig to build to validate the code does not break anything at compile time. Technically all 3 defconfigs should be built, which takes up to 4 hours right now.

Desired Additional Features

Github free minutes + free storage is too constrained for buildroot. They do hoever have self-hosted runners that integrate into the web ui just like the github-hosted ones. We should harness this configuration, along with the recently added #63, to reproduce builds both for CI checks and for creation of release binaries once releases are made as competition approaches.

Technically this could be done with a raspberrry pi plugged into a USB HDD of 128+ gb, along with a heatsink and/or aggressive temperature throttling on the pi. This would wear on the pi quick, so def we should use one of the old pi 3s.

Screenshots (as needed)

No response