Delete auto-deployed k8s objects when project is deleted

Description

With auto deploy, we create a bunch of Kubernetes deployments, replica sets, and pods for projects. When a project is deleted, we leave these objects around. We should clean them up. This is especially useful for demos where we create and destroy many projects.

Proposal

Links / references

Documentation blurb

(Write the start of the documentation of this feature here, include:

1. Why should someone use it; what's the underlying problem.
2. What is the solution.
3. How does someone use this

During implementation, this can then be copied and used as a starter for the documentation.)