Local debugging in VS Code fails after app restart

Repro steps:
1. Start a PowerShell Function app in VS Code by F5.
2. Wait for the app to start. Invoke a function or do not invoke any function - does not seem to matter.
3. Stop the app: hit the Disconnect button or push Ctrl-C in the terminal.
4. Start the app again by F5. About 2-5 seconds after the app start, it stops and the following message appears in the terminal window: `Debug-Runspace: You cannot debug the default host Runspace using this cmdlet. To debug the default Runspace use the normal debugging commands from the host.`

Further attempts to start the app fail with the same error, until VS Code is restarted.

Reproduce the failure by starting a PowerShell Function app in VS Code with F5, stopping it with Disconnect or Ctrl-C, and starting it again. Begin with the VS Code launch and terminal debugging flow around the reported Debug-Runspace message; done means repeated restarts succeed without the error and do not require restarting VS Code.

Written by the indexing model from the issue text.