Update nixpks used in flakes to a current version about ofborg

[cole-h]

Just a note that ofborg does not use the flake in this repo for evaluating / etc nixpkgs. It uses the checkout of the PR it's operating on (and/or the master nixpkgs at the time of operation). The flake only affects building the ofborg software, nothing else.

[zeuner]

This (#648) PR might be a step towards resolving the issue for the Rust part.

[zeuner]

The flake only affects building the ofborg software, nothing else.

No doubt on that (apart from maybe also running ofborg, interfacing to GitHub etc.), but since 22.05 doesn't build anymore (see e.g. NixOS/nixpkgs#277064, NixOS/nixpkgs#277158) and can't be updated (see NixOS/nixpkgs#277064 (comment)), this blocks building ofborg. If there is no need for up-to-date packages for building, having an LTS release (see https://discourse.nixos.org/t/interest-in-a-nixos-lts/4705) might reduce ofborg maintenance costs, but with the current ecosystem, updating seems to be the most straight-forward solution.

[SuperSandro2000]

Can we at least merge that PR? It is a really bad sign that our CI is in such a bad state.