Merge pull request 'flake: evaluate devShells with nixpkgs-unstable' (!107) from shell-unstable into main

Reviewed-on: #107
Reviewed-by: Oystein Kristoffer Tveit <oysteikt@pvv.ntnu.no>
Reviewed-by: Daniel Lovbrotte Olsen <danio@pvv.ntnu.no>

flake.nix

@@ -169,9 +169,9 @@
     };
 
     devShells = forAllSystems (system: {
-      default = nixpkgs.legacyPackages.${system}.callPackage ./shell.nix { };
+      default = nixpkgs-unstable.legacyPackages.${system}.callPackage ./shell.nix { };
       cuda = let
-        cuda-pkgs = import nixpkgs {
+        cuda-pkgs = import nixpkgs-unstable {
           inherit system;
           config = {
             allowUnfree = true;