fix: false-positive check for nccl install on ubuntu

[leiDnedyA]

Closes #774

I found that dpkg -l will output a version name for each package it lists, and the version name for nccl includes the substring "cuda", so I just chained another grep call and it works :)

[kschmid]

thanks for the fix. - This was haunting me just now as well (Ubuntu 22)
A pity that the PR is not yet integrated.