Runtime 49: Remove shared-modules/libusb

libusb is part of the runtime **49**. Please don't forget to remove it when the app is updated to the related runtime.

```
flatpak run --devel --command=sh org.gnome.Platform//49

grep -A 5 libusb /usr/manifest.json
"name": "components/libusb.bst",
"x-cpe": {
"product": "libusb",
"version": "1.0.29"
},
"sources": [
{
"type": "git",
"url": "https://github.com/libusb/libusb.git",
"commit": "v1.0.29-0-g15a7ebb4d426c5ce196684347d2b7cafad862626"
}
]
},
```