Add to env vars and paths

[David-OConnor]

This includes common env variables for Linux and Windows, and the latest path used on Windows.

[jorge-menjivar]

@Narsil

[Narsil]

Pretty sure we don't want any of those. Path and LD_LIBRARY_PATH should be detected automatically without requiring any manual input from this binding, since it's a core system env variable picked up by nvcc itself. So forwarding the env should be enough (without looking).

Adding 13.0 is certainly a no-go, since we don't want to add all cuda variants. If users set things up at non standard location (with version number is not standard, it's a way to manage multiple cuda versions, but the installer always put in a standard location too) then users should use CUDA_HOME which is the standard Cuda mechanisms to target non standard locations (it works with many tools).

@ivarflakstad

[David-OConnor]

Path and LD_LIBRARY_PATH should be detected automatically without requiring any manual input from this binding,

Correct, but that is not the nature of what this PR fixes. The library panics before attempting to run nvcc; see the functions this PR modifies, and the error described here.

I no longer use this library; I used it has a sub-dependency of Candle when posting this PR and its associated issue, and call nvcc using my own minimal FFI in my workflows. Follow your hearts on this one; I don't have anything more to add.