Orin Jetsons with JetPack 7 use SBSA packages, but Nixpkgs does not allow this

[hacker1024]

With JetPack 7.2, the Jetson Orin series is supported. This means that the CUDA 13 SBSA packages can be used with compute capability 8.7.

There are measures in place to prevent this from working in Nixpkgs, though.

Notably:

• getRedistSystem maps compute capability > 10.1 to SBSA (this should probably be based on isJetson and CUDA 13+ instead)
• backendStdenv has an assertion on the above behaviour, but this is also no longer accurate
• backendStdenv does not allow mixing pre and post-Thor compute capabilities, but this is now possible for Orin and Thor on CUDA 13

There may also be other places where such assumptions are made that I haven't found yet.

Resolved by #528562.