edx-platform unit tests error: Self-hosted runner loses communication with the server

A/C:

• We no longer get this error
• If fixing the error is prohibitively difficult, raise again for discussion of alternative approaches

Since roughly June 2023 we've been seeing a lot of CI failures on GitHub for edx-platform where the job is just shown as "Job failed" with no logs. But if you check the Summary view (link in the upper left) and look at the errors at the bottom of the page, the following error shows up:

The self-hosted runner: edx-platform-openedx-ci-runner-deployment-7xdl7-twcfc lost communication with the server. Verify the machine is running and has a healthy network connection. Anything in your workflow that terminates the runner process, starves it for CPU/Memory, or blocks its network access can cause this error.

These have been causing development and deployment delays. We'll need to check if there's something wrong with the runners.