Mojo relies on incompatible libtinfo

[aaronmondal]

At the moment we're getting a bunch of libtinfo-related warnings. As of the nightly version we're currently using, the Mojo SDK is built on Ubuntu 20.04. That build introduces a dependency on an old libtinfo which has no compatible equivalent in newer distros such as nixpkgs.

This dependency edge is introduced via LLVM's Support library. With llvm/llvm-project#92865 we might help upstream to get rid of this dependency, but for now we'll have to find some other workaround.