Remove VMs that fail to connect to GitHub

[bbockelm]

In the service script, we already remove idle VMs that are over threshold.

However, we don't remove VMs that fail to connect to GitHub; VMs that have some sort of runtime issue (think: landed on a host with misconfigured network) should be shut down as they are wasting resources.

Suggestion is to remove any VM that meets all of the following conditions:

1. Is in the running state.
2. Has JobCurrentStartExecutingDate set and is greater than or equal to JobCurrentStartDate (meaning the file transfers are done).
3. Has been running for at least 5 minutes.
4. Does not have a corresponding GitHub runner with status=online.