The external queries tests run in a fixed directory. This is arguably fine when run as part of CI, but if the tests are run multiple times locally then they start to interfere with each other.

To see it's working, you can see in the test logs

Cloning into '/tmp/codeql-action-1XUxpg/github/codeql-go'

This PR creates a random tmp dir for each test run and deletes it when the test is done. I created a shared function for this because I intend to start using it for other tests as well.

Also by populating the RUNNER_WORKSPACE env var we can make it required in checkoutExternalQueries and this avoids the hardcoded alternative path.

@Daverlo

Merge / deployment checklist

• Run test builds as necessary. Can be on this repository or elsewhere as needed in order to test the change - please include links to tests in other repos!
  • CodeQL using init/analyze actions - https://github.com/Anthophila/test-electron/actions/runs/96083423
  • 3rd party tool using upload action - https://github.com/Anthophila/test-electron/actions/runs/96083425
• Confirm this change is backwards compatible with existing workflows.
• Confirm the readme has been updated if necessary.