CoreUtils ls treats PowerShell drives as filesystem paths

The PowerShell integration rewrites `ls` invocations to `ls.cmd`, which breaks PowerShell provider drives such as `env:` and `alias:`.

### Repro

```powershell
ls env:
ls alias:
```

### Actual behavior

```text
ls.cmd: unknown io error: 'env:'
```

### Expected behavior

PowerShell provider drives should continue to work