[Peek] A numeric final argument in CLI mode is assumed to be the Runner PID

### Microsoft PowerToys version

0.100.2

### Installation method

GitHub

### Area(s) with issue?

Peek

### Steps to reproduce

1. Open PowerShell
2. Create a folder with a numeric name, e.g. "123"
3. Enter:

```pwsh
\PowerToys.Peek.UI.exe C:\PathToFolder\123
```

### ✔️ Expected Behavior

A preview of the folder is opened in Peek.

### ❌ Actual Behavior

Peek treats the last argument as the PowerToys Runner process ID, even if represents a file or folder which could be opened.

No UI is shown. Peek is opened, but has become a zombie process and must be closed via Task Manager:

### Upload Bug Report ZIP-file

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### Additional Information

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### Other Software

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