[LOGO] Add LeonOS 4 logo

### OS

NAME="LeonOS"
ID=leonos
PRETTY_NAME="LeonOS 4"
VERSION_ID=4

### Public repository URL

https://github.com/Leonmmcoset/LeonOS-4

### Distro Website

https://github.com/Leonmmcoset/LeonOS-4

### ASCII Art

```
$2:-------:.$1
$2:-----------.$1
$2--------------.$1 .
$2.---------------.$1 .::::
$2.-----.:------$1:::..:::::::.
$2:-----: -$1:::...::::::::::::::
$2:-----:$1 ...:::::::::::::::::::.
$2:-----.$1 .:::::::::::...:::::::::
$2----- $1 .::::........::::::::::::
$2---- $1 .::: ..::::::::::::::::::
$2:--:$1 ::. .::::::::::::::::::::
$2---$1 :. .::::::::::::::::::::.
$2:-.$1 . ::::::::::::::::::::
$2:.$1 ::::::::::::::::::
$1..::::::::::::.
```

### Original Image URL

https://github.com/Leonmmcoset/LeonOS-4-Public/blob/main/logo.png?raw=true

### Checklist

- [x] My distro has reached a stable state (out of beta, alpha, RC).
- [x] The ASCII art is smaller than 50x20 characters (W x H).
- [x] The ASCII art uses `$N` color placeholders (or colors are natively available in `os-release`).
- [x] The ASCII art has no unnecessary trailing spaces at the end of lines.
- [x] I promise that I will send a removal request if the distro is discontinued.