Uses my git.rgst.io mirror to be (hopefully) more stable that Github.
To get the list of "NUGETS" I used
<https://wiki.gentoo.org/wiki/Dotnet/Devguide#Finding_correct_NuGet_packages>.
Note that you must run it with the version of dotnet on your system
since it won't autodetect:
```bash
gdmt restore --project "$(pwd)" --sdk-ver 9.0
```
