Copilot crashes on launch if log level is set to any value other than "all" or "default"

### Describe the bug

Copilot crashes on launch if I try start it with a log level set to any of: none, error, warning, info, debug

### Affected version

_No response_

### Steps to reproduce the behavior

`copilot --log-level error`

### Expected behavior

Copilot does not crash when setting a different log level.

### Additional context

_No response_

Start with the CLI entry point and the argument handling for the --log-level option; the issue does not name a source file or test. Reproduce with `copilot --log-level error`, then check the other listed levels. Done means none, error, warning, info, and debug no longer crash on launch, while all and default continue to work.

Written by the indexing model from the issue text.