Support Self Hosted runner solution

[xunholy]

Is your feature request related to a problem? Please describe.

In certain organizations it's preferred to self-host an instance with fine-grained permissions and use a custom GitHub App to grant permissions accordingly to the repository. This could be also a stance that is enforced due to security where exfiltration of data is a concern and/or unauthorised access.

Describe the solution you'd like

I'd like to propose running this as a self-hosted instance similar to how Renovate allows you to configure it as a self-hosted GH action and BYO Github App. https://github.com/renovatebot/github-action

Describe alternatives you've considered

Currently using bespoke solution.

Additional context
Add any other context or screenshots about the feature request here.

[BenLloydPearson]

Thanks for the recommendation. This is something we will put in our product plans.