Bump shell.nix channel to 23.11

Signed-off-by: Sefa Eyeoglu <contact@scrumplex.net>

shell.nix

@@ -1,5 +1,5 @@
 let
-  nixpkgs = builtins.fetchTarball "channel:nixos-22.05";
+  nixpkgs = builtins.fetchTarball "channel:nixos-23.11";
   pkgs = import nixpkgs { config = { }; overlays = [ ]; };
 in
 with pkgs;