Github supports ephemeral runners which are limited to a single job.

You can use `workflow_job` webhook to be notified of a new job, after that you need to call `generate-jitconfig` API to get a just-in-time configuration token, and then you can start a Github runner in ephemeral mode with the JIT token.

This allows you to orchestrate Docker containers, KVM instances, etc., which are used for a single time, and then destroyed.

There are some open source projects, such as using ephemeral Kubernetes pods with the ephemeral runners.