nix: upgrade nixpkgs to v24.11

nix/merged-packages.nix

@@ -1,7 +1,7 @@
 { add_pkgs_path }:
 
 let
-    dfl_nixpkgs = import ./nixpkgs-24.05.nix {};
+    dfl_nixpkgs = import ./nixpkgs-24.11.nix {};
     dfl_python = pkgs.python312;
     null_pkgs = {
         system-packages = {};

nix/nixpkgs-24.11.nix

@@ -0,0 +1,8 @@
+import (
+    fetchGit {
+        url = "https://github.com/NixOS/nixpkgs.git";
+        ref = "release-24.11";
+        rev = "8b27c1239e5c421a2bbc2c65d52e4a6fbf2ff296"; # refs/tags/24.11
+        shallow = true;
+    }
+)

nix/shell.nix

@@ -39,6 +39,7 @@ pkgs.mkShellNoCC {
         pwd=$(pwd)
         export PYTHONPATH=$pwd
         export PATH=$pwd/cmds:$pwd/.bin-override:$HOME/.local/bin:$PATH
+        export LANG="en_US.UTF-8"
 
         [ "$UID" == 0 ] || do_bin_override
     '';

nix/user-packages.nix

@@ -8,7 +8,7 @@
 rec {
     ### Set nixpkgs globally for the MMGen environment.
     ### If you set it, make sure to uncomment the python variable assignment below.
-    # pkgs = import (bdir + /nixpkgs-24.05.nix) {};
+    # pkgs = import (bdir + /nixpkgs-24.11.nix) {};
 
     ### Set python version globally for the MMGen environment.
     ### Must be set if pkgs is set.